掺杂ZnO稳定性和电子结构的第一性原理研究
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摘要
ZnO属于Ⅱ-Ⅵ族宽带半导体，其禁带宽度为3．37eV，激子束缚能为60meV，在短波光电器件上具有很大的潜力，使得ZnO成为当今半导体材料研究领域关注的热点。在ZnO光电特性研究中，制备结型器件是ZnO薄膜实用化的关键。实现ZnO基结型器件需要满足两个基本的条件：ZnO可靠p型掺杂的实现以及通过掺杂有效地调节ZnO的能带。本文采用基于密度泛函的第一性原理方法，讨论了涉及能带工程的Cd、Be和Mg掺杂；以及涉及p型导电的Cu、Ag以及Li-N和Be-N共掺问题。通过计算这几种常见掺杂体系的晶体结构和电子结构，得到的主要研究结果如下：
1．通过对掺杂前后电子能带结构、态密度以及分态密度的计算和比较，发现Cd_xZn_(1-x)O价带顶端(VBM，conduction band minimum)始终由O-2p占据；而导带顶端(CBM，conduction band minimum)则由Cd-5s与Zn-4s杂化轨道控制。随着掺杂浓度的增加，带隙宽度的变窄由CBM位置下降和VBM位置上升共同决定，是产生荧光光谱红移的主要原因。此外，我们发现，Cd掺杂引起晶胞发生膨胀也是导致Cd_xZn_(1-x)O禁带宽度变小的原因之一，晶格膨胀对带隙减小的贡献约为20％-30％。通过研究Cd原子对ZnO中本征缺陷形成能及离化能的影响，我们发现，当Cd原子与V_O(O空位)靠近时，可以显著降低V_O的形成能，导致Cd_(Zn)-V_O复合体(其中Cd_(Zn)为Cd原子替位原子)的形成，但对其它本征缺陷的形成能影响不大。然而，计算结果显示Cd_(Zn)-V_O复合体的离化能较高，与V_O接近，不太可能是n型载流子的起源。因此，我们进一步研究了更为复杂的复合体结果，如Zn_i-Cd_(Zn)-V_O(其中Zn_i为Zn填隙)，并由此推论n型载流子的起源可能与Zn_i-Cd_(Zn)-V_O类似的复合体结构有关，如Zn_i-2Cd_(Zn)-2V_O和Zn_i-3Cd_(Zn)-3V_O等。
2．利用第一性原理计算，对Be掺杂及Mg掺杂ZnO的带结构，DOS和轨道能级进行了系统研究。结果显示，由于Be和Mg没有d电子，使得掺杂后合金的p-d排斥减弱，从而使得VBM下降。同时由于Be和Mg的最外层s点的轨道能量较高，有效地提升了合金中的CBM。VBM与CBM的共同作用使得掺杂后的ZnO带隙展宽。此外，我们研究了Be掺杂导致的合金压应变对带隙展宽的贡献，发现晶格缩小对带隙展宽的影响约为20％-30％。掺杂合金形成焓的结果计算结果显示，显示由于Mg与Zn的离子半径差别较小，Mg掺杂ZnO比Be掺杂更稳定。
3．对纤锌矿结构Cu_xZn_(1-x)O和Ag_xZn_(1-x)O的晶体结构和电子结构进行了第一性原理计算。与具有相似离子半径的Mg和Cd掺杂相比，Cu和Ag掺杂的形成焓高于Mg和Cd掺杂，合金稳定性下降。电子结构的计算结果显示，Cu和Ag掺杂导致ZnO带隙的减小。通过分析Cu和Ag掺杂ZnO的电子结构，我们发现Cu和Ag掺杂属于受主掺杂，其杂质能级位于VBM附近，重掺杂使得Cu-3d和Ag-4d电子的杂质能级展宽，并与O-2p电子占据的VBM相连接是导致ZnO带隙减小的主要贡献。因此，Cu，Ag掺杂引起的ZnO带隙减小主要发生在掺杂浓度足以使得杂质能带与VBM相连之后；一旦杂质能带与VBM相连，掺杂浓度增加对带隙的影响不大，此时，Cu-4s和Ag-5s电子对CBM的影响是带隙变化的重要原因。
4．通过计算Li，N共掺和Be，N共掺ZnO中缺陷的形成能、离化能以及结合能，发现对于Li，N共掺，在O充足的情况下，Li_(Zn)(Li替位Zn)是产生p型的原因，而在Zn充足的情况下，Li_i-Li_(Zn)-N_O复合体(其中Li_i为Li填隙，N_O为N替位O)有着相对较低的形成能和离化能，以及最低的结合能，因此可能成为这种情况下p型的起源。对于Be，N共掺ZnO，讨论了nBe_(Zn)-N_O及Be_i-nN_O两种类型的缺陷(其中Be_(Zn)为Be替位Zn，Be_i为Be填隙)。结果显示，在O充足的情况下，4Be_(Zn)-N_O是p型导电性的起源，而在Zn充足的情况下，除了4Be_(Zn)-N_O之外，Be_i-3N_O也可能是对p型导电性产生贡献。
5．通过第一性原理赝势计算对HX(Hexagonal)以及WZ(Wurtzite)ZnO的比较研究，讨论了两相在临界相变压时电子结构以及光学属性包括介电函数，折射率和吸收系数。结果显示WZ转变为HX时，能带从直接带隙变为了间接带隙，而且带隙宽度也相应的减小。HX的介电函数与WZ存在一定的不同，特别是在E／／c方向。相似的情况也出现在折射率以及吸收系数上。这些差异可以归结为HX结构在c轴上比WZ多一个键。此外对HX的电子结构以及光学属性也进行了讨论。
ZnO is a direct wide-band gap (3.37 eV) II-IV compound semiconductor with large exciton binding energy (60 meV) at room temperature. More attention has been paid to ZnO-based films due to their potential applications in optoelectronic devices in blue and ultraviolet spectra of light. A crucial step in designing modern optoelectronic device is the realization of band-gap engineering to create barrier layers and quantum wells in device heterostructures. In order to realize such optoelectronic devices, two important requirements should be satisfied: one is p-type doping of ZnO and the other is modulation of the band gap. This work is focus on the stability and electronic structure of the ZnO-based materials. Using first principle calculation, Cd, Be and Mg-doped ZnO are studied for band gap engineering. For p type doping, Cu, Ag-doped and Li-N, Be-N co-doped ZnO are studied. The results are summarized as follow:
1. Analysis of the band structures, density of states (DOS) and partial density of states (PDOS) of Cd_xZn_(1-x)O shows that the valence band maximum (VBM) is determined by O-2p states and the conduction band minimum (CBM) is occupied by the hybrid Cd-5s and Zn-4s orbital. With increasing Cd-doping concentrations, the energies of CBM decrease and the energies of VBM increase, hence leading to narrowing of the band gap. Furthermore, we find that the reduction of band gap due to Cd-doping can be attributed to the tensile strain, which is about 20-30% in the reduction of the band gap. We also study the interaction between Cd and native defects. It is found that the Cd incorporation can lower the formation energy of V_o defect and results in the production of Cd_(Zn)-V_o complex when the Cd dopant is close to V_o. The high transition level, however, suggests that the Cd_(Zn)-V_o complex cannot be the source resulting in the increase of the concentration of n-type carriers due to Cd doping. We study a more complicated structure Zn_i-Cd_(Zn)-V_o and suggest that the increase of n-type carriers caused by Cd doping might result from a structure similar to Zn_i-Cd_(Zn)-V_o, such as Zn_i-2Cd_(Zn)-2V_o and Zn_i-3Cd_(Zn)-3V_o.
2. The band structure, DOS, and orbital energy level of Be-doped and Mg-doped ZnO are investigated. The results show that the absence of d electrons in Be and Mg can weaken p-d repulsion, hence resulting in the decrease of VBM in the doped ZnO. The energy levels of CBM are found increasing in the doped ZnO. The increase can be attributed to the higher orbital energy levels of s electrons in Be and Mg atoms. In addition, Be-doping can cause compressive strain, causing the increase of band gap about 20%-30%. The formation enthalpy of alloy is also discussed. Mg-doped ZnO is more stable than Be-doped ZnO due to the little difference in radii between Mg and Zn ions.
3. The electronic structures of the Cu_xZn_(1-x)O and Ag_xZn_(1-x)O wurtize alloys are calculated. Although Cu and Ag have the similar ion radius with Mg and Cd, respectively, the formation enthalpy of Cu-doped and Ag-doped ZnO is found to be higher than Mg-doped and Cd-doped ZnO. The results of electronic structures show that Cu-doped and Ag-doped ZnO have narrower band gap than ZnO, which can be attributed to the extension of impurity levels induced by Cu-3d and Ag-4d. Because the impurity levels is close to the VBM of ZnO, heavy doping results in the impurity levels extending to the VBM and merging into one band. Therefore, the reduction of band gap appears sharply at a concentration of Cu or Ag dopant. Thereafter, the band gap varies slowly, which can be attributed to the influence of Cu-4s or Ag-5s electrons on the CBM energy.
4. Formation energy, transition energy and binding energy of defects in Li, N and Be, N co-doped p-type ZnO are calculated. For Li, N co-doped ZnO, it is found that Li_(Zn) is the cause of p-type conductivity in O-rich condition. The p-type conductivity is dominated by the Li_i-Li_(Zn)-No in Zn-rich condition because it has relatively small formation energy and transition energy and lowest binding energy. For Be, N co-doped ZnO, nBe_(Zn)-N_o and Be_i-nN_o are discussed. In O-rich condition, acceptor 4Be_(Zn)-N_o may be the source of p-type conductivity. In Zn-rich condition, both of 4Be_(Zn)-N_o and Be_i-5N_o are found to be the most possible candidates to provide the p-type conductivity.
5. First-principles ultrasoft pseudopotential method is applied to study HX ZnO, which has a novel graphitelike hexagonal structure transformed from wurtzite phase under tensilestress along [01 (?) 0] direction or compressive stress along [0001] direction. The electronic structure and optical properties, including dielectric function, reflectivity and absorption coefficient, of HX ZnO are calculated and compared with those of WZ ZnO under the given uniaxial stress. It is found that HX ZnO is an indirect semiconductor, being different from WZ ZnO. HX ZnO has a dielectric response different from WZ ZnO at ambient conditions or under the given uniaxial stress, especially in the case of E//c. Similar variation is also observed in the reflectivity and absorption coefficient. The variation in the optical properties is attributed to the additional Zn-0 bond along c-axis HX ZnO. In addition, the electronic structure and optical properties of LY ZnO are reported.
1．通过对掺杂前后电子能带结构、态密度以及分态密度的计算和比较，发现Cd_xZn_(1-x)O价带顶端(VBM，conduction band minimum)始终由O-2p占据；而导带顶端(CBM，conduction band minimum)则由Cd-5s与Zn-4s杂化轨道控制。随着掺杂浓度的增加，带隙宽度的变窄由CBM位置下降和VBM位置上升共同决定，是产生荧光光谱红移的主要原因。此外，我们发现，Cd掺杂引起晶胞发生膨胀也是导致Cd_xZn_(1-x)O禁带宽度变小的原因之一，晶格膨胀对带隙减小的贡献约为20％-30％。通过研究Cd原子对ZnO中本征缺陷形成能及离化能的影响，我们发现，当Cd原子与V_O(O空位)靠近时，可以显著降低V_O的形成能，导致Cd_(Zn)-V_O复合体(其中Cd_(Zn)为Cd原子替位原子)的形成，但对其它本征缺陷的形成能影响不大。然而，计算结果显示Cd_(Zn)-V_O复合体的离化能较高，与V_O接近，不太可能是n型载流子的起源。因此，我们进一步研究了更为复杂的复合体结果，如Zn_i-Cd_(Zn)-V_O(其中Zn_i为Zn填隙)，并由此推论n型载流子的起源可能与Zn_i-Cd_(Zn)-V_O类似的复合体结构有关，如Zn_i-2Cd_(Zn)-2V_O和Zn_i-3Cd_(Zn)-3V_O等。
2．利用第一性原理计算，对Be掺杂及Mg掺杂ZnO的带结构，DOS和轨道能级进行了系统研究。结果显示，由于Be和Mg没有d电子，使得掺杂后合金的p-d排斥减弱，从而使得VBM下降。同时由于Be和Mg的最外层s点的轨道能量较高，有效地提升了合金中的CBM。VBM与CBM的共同作用使得掺杂后的ZnO带隙展宽。此外，我们研究了Be掺杂导致的合金压应变对带隙展宽的贡献，发现晶格缩小对带隙展宽的影响约为20％-30％。掺杂合金形成焓的结果计算结果显示，显示由于Mg与Zn的离子半径差别较小，Mg掺杂ZnO比Be掺杂更稳定。
3．对纤锌矿结构Cu_xZn_(1-x)O和Ag_xZn_(1-x)O的晶体结构和电子结构进行了第一性原理计算。与具有相似离子半径的Mg和Cd掺杂相比，Cu和Ag掺杂的形成焓高于Mg和Cd掺杂，合金稳定性下降。电子结构的计算结果显示，Cu和Ag掺杂导致ZnO带隙的减小。通过分析Cu和Ag掺杂ZnO的电子结构，我们发现Cu和Ag掺杂属于受主掺杂，其杂质能级位于VBM附近，重掺杂使得Cu-3d和Ag-4d电子的杂质能级展宽，并与O-2p电子占据的VBM相连接是导致ZnO带隙减小的主要贡献。因此，Cu，Ag掺杂引起的ZnO带隙减小主要发生在掺杂浓度足以使得杂质能带与VBM相连之后；一旦杂质能带与VBM相连，掺杂浓度增加对带隙的影响不大，此时，Cu-4s和Ag-5s电子对CBM的影响是带隙变化的重要原因。
4．通过计算Li，N共掺和Be，N共掺ZnO中缺陷的形成能、离化能以及结合能，发现对于Li，N共掺，在O充足的情况下，Li_(Zn)(Li替位Zn)是产生p型的原因，而在Zn充足的情况下，Li_i-Li_(Zn)-N_O复合体(其中Li_i为Li填隙，N_O为N替位O)有着相对较低的形成能和离化能，以及最低的结合能，因此可能成为这种情况下p型的起源。对于Be，N共掺ZnO，讨论了nBe_(Zn)-N_O及Be_i-nN_O两种类型的缺陷(其中Be_(Zn)为Be替位Zn，Be_i为Be填隙)。结果显示，在O充足的情况下，4Be_(Zn)-N_O是p型导电性的起源，而在Zn充足的情况下，除了4Be_(Zn)-N_O之外，Be_i-3N_O也可能是对p型导电性产生贡献。
5．通过第一性原理赝势计算对HX(Hexagonal)以及WZ(Wurtzite)ZnO的比较研究，讨论了两相在临界相变压时电子结构以及光学属性包括介电函数，折射率和吸收系数。结果显示WZ转变为HX时，能带从直接带隙变为了间接带隙，而且带隙宽度也相应的减小。HX的介电函数与WZ存在一定的不同，特别是在E／／c方向。相似的情况也出现在折射率以及吸收系数上。这些差异可以归结为HX结构在c轴上比WZ多一个键。此外对HX的电子结构以及光学属性也进行了讨论。
ZnO is a direct wide-band gap (3.37 eV) II-IV compound semiconductor with large exciton binding energy (60 meV) at room temperature. More attention has been paid to ZnO-based films due to their potential applications in optoelectronic devices in blue and ultraviolet spectra of light. A crucial step in designing modern optoelectronic device is the realization of band-gap engineering to create barrier layers and quantum wells in device heterostructures. In order to realize such optoelectronic devices, two important requirements should be satisfied: one is p-type doping of ZnO and the other is modulation of the band gap. This work is focus on the stability and electronic structure of the ZnO-based materials. Using first principle calculation, Cd, Be and Mg-doped ZnO are studied for band gap engineering. For p type doping, Cu, Ag-doped and Li-N, Be-N co-doped ZnO are studied. The results are summarized as follow:
1. Analysis of the band structures, density of states (DOS) and partial density of states (PDOS) of Cd_xZn_(1-x)O shows that the valence band maximum (VBM) is determined by O-2p states and the conduction band minimum (CBM) is occupied by the hybrid Cd-5s and Zn-4s orbital. With increasing Cd-doping concentrations, the energies of CBM decrease and the energies of VBM increase, hence leading to narrowing of the band gap. Furthermore, we find that the reduction of band gap due to Cd-doping can be attributed to the tensile strain, which is about 20-30% in the reduction of the band gap. We also study the interaction between Cd and native defects. It is found that the Cd incorporation can lower the formation energy of V_o defect and results in the production of Cd_(Zn)-V_o complex when the Cd dopant is close to V_o. The high transition level, however, suggests that the Cd_(Zn)-V_o complex cannot be the source resulting in the increase of the concentration of n-type carriers due to Cd doping. We study a more complicated structure Zn_i-Cd_(Zn)-V_o and suggest that the increase of n-type carriers caused by Cd doping might result from a structure similar to Zn_i-Cd_(Zn)-V_o, such as Zn_i-2Cd_(Zn)-2V_o and Zn_i-3Cd_(Zn)-3V_o.
2. The band structure, DOS, and orbital energy level of Be-doped and Mg-doped ZnO are investigated. The results show that the absence of d electrons in Be and Mg can weaken p-d repulsion, hence resulting in the decrease of VBM in the doped ZnO. The energy levels of CBM are found increasing in the doped ZnO. The increase can be attributed to the higher orbital energy levels of s electrons in Be and Mg atoms. In addition, Be-doping can cause compressive strain, causing the increase of band gap about 20%-30%. The formation enthalpy of alloy is also discussed. Mg-doped ZnO is more stable than Be-doped ZnO due to the little difference in radii between Mg and Zn ions.
3. The electronic structures of the Cu_xZn_(1-x)O and Ag_xZn_(1-x)O wurtize alloys are calculated. Although Cu and Ag have the similar ion radius with Mg and Cd, respectively, the formation enthalpy of Cu-doped and Ag-doped ZnO is found to be higher than Mg-doped and Cd-doped ZnO. The results of electronic structures show that Cu-doped and Ag-doped ZnO have narrower band gap than ZnO, which can be attributed to the extension of impurity levels induced by Cu-3d and Ag-4d. Because the impurity levels is close to the VBM of ZnO, heavy doping results in the impurity levels extending to the VBM and merging into one band. Therefore, the reduction of band gap appears sharply at a concentration of Cu or Ag dopant. Thereafter, the band gap varies slowly, which can be attributed to the influence of Cu-4s or Ag-5s electrons on the CBM energy.
4. Formation energy, transition energy and binding energy of defects in Li, N and Be, N co-doped p-type ZnO are calculated. For Li, N co-doped ZnO, it is found that Li_(Zn) is the cause of p-type conductivity in O-rich condition. The p-type conductivity is dominated by the Li_i-Li_(Zn)-No in Zn-rich condition because it has relatively small formation energy and transition energy and lowest binding energy. For Be, N co-doped ZnO, nBe_(Zn)-N_o and Be_i-nN_o are discussed. In O-rich condition, acceptor 4Be_(Zn)-N_o may be the source of p-type conductivity. In Zn-rich condition, both of 4Be_(Zn)-N_o and Be_i-5N_o are found to be the most possible candidates to provide the p-type conductivity.
5. First-principles ultrasoft pseudopotential method is applied to study HX ZnO, which has a novel graphitelike hexagonal structure transformed from wurtzite phase under tensilestress along [01 (?) 0] direction or compressive stress along [0001] direction. The electronic structure and optical properties, including dielectric function, reflectivity and absorption coefficient, of HX ZnO are calculated and compared with those of WZ ZnO under the given uniaxial stress. It is found that HX ZnO is an indirect semiconductor, being different from WZ ZnO. HX ZnO has a dielectric response different from WZ ZnO at ambient conditions or under the given uniaxial stress, especially in the case of E//c. Similar variation is also observed in the reflectivity and absorption coefficient. The variation in the optical properties is attributed to the additional Zn-0 bond along c-axis HX ZnO. In addition, the electronic structure and optical properties of LY ZnO are reported.
引文
[1] Zu P, Tang Z K, Wong G K L, et al. Ultraviolet spontaneous and stimulated emissions from ZnO microcrystallite thin films at room temperature. Solid State Commun., 1997,103:459-463.
[2] Bagnall D M, Chen Y F, Zhu Z, et al. Optically pumped lasing of ZnO at room temperature Appl. Phys. Lett., 1997,70:2230-2232.
[3] Miller P M, Jr. in Proc. Intern. Conf. on Semiconducting Materials Reading (1950) (Ed.: H. K. Henisch), Butterworths, London, 1951, p. 172.
[4] Brown H E, Zinc Oxide Rediscovered, The New Jersey Zinc Company,New York, 1957; and Zinc Oxide Properties and Applications, Pergamon, New York, 1976.
[5] Ozgur 0, Alivov Y I, Liu C, et al. A comprehensive review of ZnO materials and devices. J. Appl. Phys., 2005,98:041301-041404.
[6] Jaffe J E and Hess A C. Hartree-Fock study of phase changes in ZnO at high pressure. Phys. Rev. B, 1993,48:7903-7909.
[7] Jaffe J E, Snyder J A, Lin Z, et al. LDA and GGA calculations for high-pressure phase transitions in ZnO and MgO. Phys. Rev. B, 2000,62: 1660-1665.
[8] Boca Raton. CRC Handbook of Chemistry and Physics, 58th ed. CRC Press, 1977.
[9] Dulub O, Boatner L A, Diebold U Surf. Sci., 2002 519:201
[10] Phillips J C, Bonds and Bands in semiconductors.Academic, New York, 1973
[11] Lide D R(Ed,), CRC Handbook of Chemistry and Physics, 73th ed. CRC Press, 1992
[12] Kisi E H, Elcombe, Acta Cryst. 1989 C45:1867
[13] Gerward L, Olsen J S, J. Synchrotron Radiat. 1995 2:233
[14] Bates C H, White W B, and Roy R. New high-pressure polymorph of zinc oxide. Science, 1962, 137: 993-996.
[15] Recio J M, Blanco M A, Luana V et al. Compressibility of the high-pressure rocksalt phase of ZnO. Phys. Rev. B, 1998, 58: 8949-8954
[16] Jamieson J C, Phys. Earth Planet. Inter. 1970,3:201
[17] Desgreniers S. Structural and compressive parameters High-density phases of ZnO: Phys. Rev. B 1998 58:14102-14105
[18] Chen M, Wang X, Yu YH, et al. X-ray photoelectron spectroscopy and auger electron spectroscopy studies of Al-doped ZnO films. Appl. Surf. Sci., 2000,158(1-2):134-140.
[19] Minami T, Sato H, Nanto et al., Heat treatment in hydrogen gas and plasma for transparent conducting oxide films such as ZnO, SnO_2 and indium tin oxide. Thin Solid films, 1989,176:277-281.
[20] Klingshirn C. Semiconductor Optics, 3rd ed., Springer, Heidelberg, 2006
[21] Rossler U (ED.) Landolt-Bornstein, New Series, Group III, Vol. 17 B, 22, 41B, Springer, Heidelberg, 1999.
[22] Osinsky A, Dong J W, Kauser, et al. MgZnO/AlGaN heterostructure light-emitting diodes. Appl. Phys. Lett., 2004,85: 4272-4274
[23] Liu Y, Gorla C R, Liang S, et al. Ultraviolet detectors based on epitaxial ZnO films grown by MOCVD, J Elec Mater, 2000,29(1): 69-74.
[24] Look D C, Reynolds D C, Hemsky J M., Production and annealing of electron irradiation damage in ZnO. Appl.Phys.Lett., 1999, 75(6):811-813.
[25] Hoffman R L, ZnO-channel thin-film transistors: Channel mobility J. Appl. Phys. 2004,95:5813-5819
[26] Fortunato E M C, Barquinha P M C, Pimental A C M P G, et al. Fully Transparent ZnO Thin-Film Transistor Produced at Room Temperature, Adv. Mater. 2005,17:590-594
[27] Wang H T, Rang B S, Ren F et al. Hydrogen-selective sensing at room temperature with ZnO nanorods. Appl. Phys. Lett. 2005 86:243503-243505
[28] Pearton S J, Heo W H, Norton D P, et al. Dilute magnetic semiconducting oxides. 2004 19:R59-R74
[29] Bertram F, Giemsch S, Fortser et al. Direct imaging of phase separation in ZnCdO layers. Appl. Phys. Lett. ,2006 88:061915
[30] Sakurai K, Takagi T, Kubo T et al. Spatial composition fluctuations in blue-luminescent ZnCdO semiconductor films grown by molecular beam epitaxy. J. Crys. Grow. 2002 237-239:514-517
[31] Ma D W, Ye Z Z, Chen L L. Dependence of structural and optical properties of Znl-xCdxO films on the Cd composition. Phys. Status Solidi (a) 2004 201:2929-2933
[32] Makino T, Segawa Y, Kawasaki M, et al, Band gap engineering based on Mg_xZn_(1-x)O and Cd_yZn_(1-y)O ternary alloy films,, Appl. Phys. Lett., 200178:1237-1239
[33] Ohtomo A, Kawasaki M, Koida T, et al, Mg_xZn_(1-x)O as a II -VI widegap semiconductor alloy, Appl. Phys. Lett., 1998 72:2466-2468.
[34] Choopun S, Vispute R D, Yang W, et al, Realization of band gap above 5.0 eV in metastable cubic-phase MgxZnl-xO alloy films,, Appl. Phys. Lett., 2002 80:1529-1531.
[35] Chen J, Shen W Z, Long-wavelength optical phonon properties of ternary MgZnO thin films, Appl. Phys. Lett., 2003 83:2154-2156.
[36] Ryu Y R, Lee T S, Lubguban J A, et al. Wide-band gap oxide alloy: BeZnO Appl. Phys . Lett. 2006 88:052103.
[37] Ryu Y R, Lee T S, Lubguban J A, et al. Next generation of oxide photonic devices: ZnO-based ultraviolet light emitting diodes. Appl. Phys . Lett. 2006 88:241108
[38] Service R F. Will UV lasers beat the blues?. Science, 1997,276(5314): 895.
[39] Kohan A F, Ceder G, Morgan D, et al. First-principle study of point defects in ZnO. Phys. Rev. B 2000 61:15019-15027
[40] Van de Walle C G.. Hydrogen as a Cause of Doping in Zinc Oxide. Phys. Rev. Lett. 2000 85:1012-1015
[41] Myong D Y, Baik D J, Lee C H, et al. Extremely Transparent and Conductive ZnO:Al Thin Films Prepared by Photo-Assisted Metalorganic Chemical Vapor Deposition (photo-MOCVD) Using AlCl_3(6H_2O) as New Doping Material. Jpn. J. Appl. Phys., Part 2 2007 36:L1078-L1081
[42] Ataev B M, Bagamadova A M, Djabrailov A M, et al. Highly conductive and transparent Ga-doped epitaxial ZnO films on sapphire by CVD. Thin Solid Film 1995 260:19-20
[43] Van der Walle C G, Laks D B, Neumark G F, et al. First-principles calculations of solubilities and doping limits: Li, Na, and N in ZnSe. Phys. Rev. B 1993 47:9425-9434
[44] Look D C, Jones R L, Sizelove J R, et al. The path to ZnO devices: donor and acceptor dynamics. Physica Status Solidi (a) 2003 195:171-177
[45] Park C H, Zhang S B, Wei S H. Origin of p-type doping difficulty in ZnO: The impurity perspective. Phys. Rev. B 2002 67:073202
[46] Ahn B D, Kang H S, im J H, et al. Synthesis and analysis of Ag-doped ZnO. J. Appl. Phys. 2006 100:093701
[47] Ahn B D, Deutsch T, Tan T F, et al. Synthesis of band-gap-reduced p-type ZnO films by Cu incorporation. J. Appl. Phys. 2007 102:023517
[48] Kobayashi A, Sankey O F, Dow J D, et al. Deep energy levels of defects in the wurtzite semiconductors AIN, CdS, CdSe, ZnS, and ZnO. Phys. Rev. B 1983 28:946-956
[49] Wu Z L, Merz J L, Werkhoven C J, et al. Shallow N acceptor in N+-implanted ZnSe. Appl. Phys. Lett. 1982 40:345-347
[50] Iwata K, Fons P, Yamada A, et al. Nitrogen-induced defects in ZnO: N grown on sapphire substrate by gas source MBE. J. Cryst. Growth 2000 209:526-531
[51] Look D C, Reynolds D C, Litton C W, et al. Characterization of homoepitaxial p-type ZnO grown by molecular beam epitaxy. Appl. Phys. Lett. 2002 81:1830-1832
[52] Ashrafi A B M A, Suemune I, Kumano H, et al. Nitrogen-Doped p-Type ZnO Layers Prepared with H2O Vapor-Assisted Metalorganic Molecular-Beam Epitaxy. Jpn. J. Appl. Phys. 2002 41:L1281-L1284
[53] Vaithianathan V, Lee B T, Chang C H, et al. Characterization of As-doped, p-type ZnO by x-ray absorption near-edge structure spectroscopy. Appl. Phys. Lett. 2006 88:112103
[54] Vaithianathan V, Lee B T, Kim S S, Preparation of As-doped p-type ZnO films using a Zn3As2 /ZnO target with pulsed laser deposition. Appl. Phys. Lett. 2005 86:062101
[55] Aoki T, Hatanaka Y, Look D C. ZnO diode fabricate by excimer-laer doping Appl. Phys. Lett. 2000 76:3257-3259
[56] Jaffe J E, Snyder J A, Lin Z, et al. LDA and GGA calculations for high-pressure phase transitions in ZnO and MgO. Phys. Rev. B, 2000, 62: 1660-1665.
[57] Nishidate K, Yoshizawa M, Hasegawa M. Energetics of Mg and B adsorption on polar zinc oxide surfaces from first principles. Phys. Rev. B, 2008, 77:035330
[58] Fan W, Xu H, Rosa A L, et al. First-principles calculations of reconstructed [0001] ZnO nanowires. Phys. Rev. B, 2007,76: 073302.
[59] Chanier T, Opahle I, Sargolzaei M, et al. Magnetic State around Cation Vacancies in II—VI Semiconductors. Phys. Rev. Lett. 2008 100:026405
[60] Fan X F, Zhu Z X, Ong Y S, et al. A direct first principles study on the structure and electronic properties of Be_xZn_(1-x)O. Appl. Phys. Lett. 2007 91:121121.
[61] Ding S F, Fan G H, Li S T, et al. Theoretical study of Be_xZn_(1-x)O alloys. Physica B 2007 394:127-131.
[62] Fan X F, Sun H D, Shen Z X, et al. A first-principle analysis on the phase stabilities, chemical bonds and band gaps of wurtzite structure A_xZn_(1-x)O alloys (A = Ca, Cd, Mg) J. Phys.: Condens. Matter 2008 20:235221
[63] Gopal P, Spaldin N A. Magnetic interactions in transition-metal-doped ZnO: An ab initio study. Phys. Rev. B 2006 74:094418
[64] Patterson C H. Role of defects in ferromagnetism in Zn_(1-x)Co_xO: A hybrid density-functional study. Phys. Rev. B 2006 74:144432
[65] Debermardi A, Fanciulli M. Ab initio study of magnetic interaction of Fe doped ZnO with intrinsic vacancies. Appl. Phys. Lett. 207 90: 212510.
[66] Minegishi, K., Koiwai, Y., Kikuchi Y. et al. Growth of p-type zinc oxide films by chemical vapor deposition. Jpn. J. Appl. Phys., Part 2:Letters, 1997,36 (11 PART A): L1453-L1455.
[67] Zhang S B, Northrup J E. Chemical potential dependence of defect formation energies in GaAs: Application to Ga self-diffusion. Phys. Rev. Lett. 1991 67:2339-2342
[68] Laks D B, Van der Walle C G, Neumark G F, et al. Native defects and self-compensation in ZnSe. Phys. Rev. B 1992 45:10965
[69] Wei S H. Overcoming the doping bottleneck in semiconductors. Comp. Mater. Sci. 2004 30:337-348
[70] Van der Walle, C G, Neugebauer J. First-principles calculations for defects and impurities: Applications to III-nitrides. J Appl. Phys. 2004 95:3851-3879
[71] Yan Y F, Zhang S B, Panteldes. Control of doping by Impurity Chemical Potential: Predictions for p-type ZnO Phys. Rev. Lett. 2001 86:5723-5726
[72] Yan Y F, Al-Jassim M M, Wei S H. Doping of ZnO by group-IB elements. Appl. Phys. Lett. 2006 89:181912
[73] Limpijumnong S, Zhang S B, Wei S H, et al. Doping by Large-Size-Mismatched Impurities: The Microscopic Origin of Arsenicor Antimony-Doped p-Type Zinc Oxide. Phys. Rev. Lett. 2004 92:155504
[74] Park C H, Zhang S B, Wei S H. Origin of p-type doping difficulty in ZnO: The impurity perspective. Phys. Rev. B 2002 66:073202
[75] Li J B, Wei S H, Li S S, et al. Design of shallow acceptors in ZnO: First-principles band-structure calculations. Phys. Rev. B 2006 74:081201
[76] Yan Y F, Li J B, Wei S H, et al Possible Approach to Overcome the Doping Asymmetry in Wideband Gap Semiconductors. Phys. Rev. Lett. 2007 98:135506
[77] The 1998 Nobel Prize in chemisty: heep://www.nobel.se/chemistry/laureates/1998/; also see: Kohn W, Rev. Mod. Phys. 71 (1999) 1253
[78] Born M, Oppenheimer R, ZUT quantentheorie der Molekeln. Ann. Phys. 1927, 84:457-484
[79] Hartree D R, Proc. Cam. Phil. Soc. 24 (1928) 89
[80] Szabo A, Ostlun N S, Modern quantum chemistry - introduction to advance electronic structure theory. New York: McGraw-Hill 1989
[81] Fock V, Z. Phys. 61 (1930) 209
[82] Slater J C, Quantum Theory of Atomic Structure, New York, McGraw-Hill, 1960
[83] Hohenberg P, Kohn W. Inhomogeneous electron gas. Phys. Rev. 1964,136: B864-871
[84] Kohn W, Sham L J. Selfe-consistant equations including exchange ang correlation effects. Phys. Rev. 1965, 140:A1133-1138
[85]Janak J F. Proof that (?)E/(?)ni=ε in density-functional theory. Phys. Rev. B 1978 18: 7165-7168
[86] Hedin L and Lundqvist B I. Explicit local exchange-correlation potentials. J. Phys. C: solid state phys. 19714:2064-2083
[87] Ceperley D M and Alder B J. Ground State of the Electron Gas by a Stochastic Method. Phys. Rev. Lett. 1980 45,566-569
[88] Perdew J P, Zunger A. Self-interaction correction to density-functional approximations for many-electron systems. Phys. Rev. B 1981 23: 2048-6079
[89] Perdew J P, Wang Y. Accurate and simple analytic representation of the electron-gas correlation energy. Phys. Rev. B. 1992 45:13244-13249
[90] Harris J, Jones R O. The surface energy of a bounded electron gas. J. Phys. F 1974 4:1170-1186
[91] Gunnarsson O, Lundqvist B I. Exchange and correlation in atoms, molecules, and solids by the spin-density-functional formalism. Phys. Rev. B 1976 13:4274-4298
[92] Langreth D C, Perdew J P. Exchange-correlation energy of a metallic surface: Wave-vector analysis. Phys. Rev. B 15:2884-2901
[93] Langreth D C, Mehl M J. Easily Implementable Nonlocal Exchange-Correlation Energy Functional. Phys. Rev. Lett. 1981 47:446-450
[94] Perdew J P, Chevary J A, Vosko S H, Jaekson K A, Singh D J, Fiolhais C. Atoms, molecules, solids. and surface: Applications of the generalized gradient approximation of exchange and correlation. Phys. Rev. B 1992 46:6671-6687
[95] Perdew J P, Wang Y. Accurate and simple density functional for the electronic exchange energy: Generalized gradient approximation. Phys. Rev. B 1986 33: 8800-8802
[96] Perdew J P. Density-functional approximation for the correlation energy of the inhomogeneous electron gas. 1986 Phys. Rev. B 33:8822-8824
[97] Perdew J P, Wang Y. Accurate and simple analytic representation of the electron-gas correlation energy. Phys. Rev. B 1992 45: 13244-13249
[98] Perdew J P, Burke K, Ernzerhof M. Generalized Gradient Approximation Made Simple. Phys. Rev. Lett. 1996 77:3865-3868
[99] Perdew J P, Burke K, Ernzerhof M. Generalized Gradient Approximation Made Simple. Phys. Rev. Lett. 1996 78: 1396-1397 (Erratum)
[100] Lieb E H, Oxford S. Int. J. Quantumn Chem. 1981 19:427
[101] Becke A D. Density-functional exchange-energy approximation with correct asymptotic behavior. Phys.Rev. A 1988 38:3098-3100
[102] Lee C, Yang W, Parr R G. Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density. Phys. Rev. B 1988 37: 785-789
[103] Ashcroft N W, Mermin N D. Solid State Physics. Philadelphia, Holt Sauders, 1976, p113
[104] Monkhorst H J, Pack J D. Special points for Brillouin-zone integrations, Phys. Rev. B, 1976 13: 5188-5192.
[105] Monkhorst H J, Pack J D. Special points for Brillouin-zone integrations - a reply, Phys. Rev. B, 1977 1:1748-1749
[106] Robertson I J, Payne M C. k-point sampling and the k.p method in pseudopotential total energy calculations. J. Phys.: Condens. Matter 1990 2:9837-9852
[107] Robertson I J, Payne M C. The k.p method in pseudopotential total energy calculations: error reduction and absolute energies. J. Phys.: Condens. Matter 1991 3: 8841-8853
[108] Phillpe J C. Energy-Band Interpolation Scheme Based on a Pseudopotential. Phys. Rev. 1958 112: 685-695
[109] Cohen M L and Heine. The fitting of pseudopotentials to experimental data and their subsequent application, in Solid State Physics, Vol. 24, eds. H. Ehrenreich, F. Seitz, and D. Turnbull (Academic Press, New York, 1970), p.37.
[110] Yin M T and Cohen M L. Theory of ab initio pseudopotential calculations Phys. Rev. B 1982 25: 7403-7412
[111] Vanderbilt D, Soft self-consistent pseudopotentials in generalized eigenvalue formalism. Phys. Rev. B 1990 41:7892-7895
[112] Blochl P E, Projector augmented-wave method. Phys. Rev. B 1994 50: 17953-17979
[113] Kresse G, Joubert D, From ultrasoft pseudopotentials to the projector augmented-wave method. Phys. Rev. B 1999 59:1758-1775
[114] Rappe A K, Rabe K, Kaxiras E, Joannopolous J D, Optimized pseudopotentials, Phys. Rev. B 1990 41:1227-1230
[115] Lin J S, Qteish A, Payne M C, Heine V, Optimized and transferable nonlocal separable ab initio pseudopotentials, Phys. Rev. B 1993 47:4174-4180
[116] Keinmann L, Bylander D M Phys. Efficacious Form for Model Pseudopotentials, Rev. Lett 1982 48: 1425-1428
[117] King-Simth R D, Payne M C lin J S Real-space implementation of nonlocal pseudopotentials for first-principles total-energy calculations, Phys. Rev. B 1991 44: 13063-13066
[118] Kresse G Fuhrtmuller J, Efficient iterative schemes for ab initio total energy calculations using a plane-wave basis set. Phys. Rev. B 1996 54: 11169-11186
[119] Kresse G Fuhrtmuller J, Efficiency of ab initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comp. Mat. Sci. 1996 6: 15-50
[120] Decremps F, Dathi F, Poloan A, et al. Local structure of condensed zin oxide. Phys. Rev. B 2003 68:104101
[121] Schleife A, Fuchs F, Furthmuller J, et al. First-principles study of ground- and excited-state properties of MgO, ZnO, and CdO polymorphs. Phys. Rev. B 2006 73:245212
[122] Jaffe E, Snydern J A, Lin Z. et al. LDA and GGA calculations for high-pressure phase transitions in ZnO and MgO. Phys. Rev. B 2000 62:1660-1665
[123] Guerrero-Moreno R J, Takeuchi N. First principles calculations of the ground-state properties and structural phase transformation in CdO. Phys. Rev. B 2002 66:205205
[124] Janotti A, Segev D and Van der Walle C G. Effects of cation d states on the structural and electronic properties of Ill-nitride and H-oxide wide-band-gap semiconductors. Phys. Rev. B 2007 74:045202
[125] Vladimir I A, Aryasetiawan F and Lichtenstein A I. First-principles calculations of the electronic structure and spectra of strongly correlated systems: the LDA+ U method. J. phys. Condens. Mater. 1997 9:767-808
[126] Osuch K, Lombardi E B, Gebicki W. First principles study of ferromagnetism in Ti_(0.0625)Zn_(0.9357)O. Phys. Rev. B 2006 73:075202
[127] Moon C Y, Wei S H, Zhu Y Z, et al. Band-gap bowing coefficients in large size-mismatched II-VI alloys: first-principles calculations. Phys. Rev. B 2006 74:233202.
[128] Sun C W, Xin P, Ma C Y et al. Optical and electrical properties of Cd_xZn_(1-x)O films grown on Si substrates by reactive radio-frequency magnetron sputtering. Appl. Phys. Lett. 2006 89:181923
[129] Persson C. Strong Valence-Band Offset Bowing of ZnO_(1_x)S_X Enhances p-Type Nitrogen Doping of ZnO-like Alloys. Phys. Phys. Lett. 2006 97:146403
[130] Zhang X D, Guo M L, Li W X et al. First-principle study of electronic and optical properties in wurtzite Cd_xZn_(1-x)O. J. Appl. Phys. 2008 103:063721
[131] Zuniga-Pérez J, Munoz-Sanjose V, Lorenz M, et al., G. Benndort, S. Heitsch, D. Spemann, and M. Grundmann, Structural characterization of a-plane Zn_(1-x)Cd_xO (0≤x≤0.085) thin films grown by metal-organic vapor phase epitaxy. J. Appl. Phys. 2006 99:023514
[132] Ishihara J, Nakamura A, Shigemori S, et al. Zn_(1-x)Cd_xO systems with visible band gap. Appl. Phys. Lett. 2006 89:091914.
[133] Delley B. From molecular to solid with the DMol3 approach. J. Chem. Phys. 2000 113:7756
[134] Janotti A, Van der Walle C G. Absolute deformation potentials and band alignment of wurtzite ZnO, MgO, and CdO. Phys. Rev. B 2007 75:121201
[135] Wei S H, Zunger A. Role of metal d states in II-VI semiconductors. Phys. Rev. B 1988 37:8958-8981
[136] Wei S H, Zunger A. Calculated natural band offsets of all II-VI and III—V semiconductors: Chemical trends and the role of cation d orbitals Appl. Phys. Lett. 1998 72:2011
[137] Ma D W, Ye Z Z, Chen L L. Dependence of structural and optical properties of Zn_(1-x)Cd_xO films on the Cd compositionPhys. Status Solidi A 2004 201:2929
[138] Ghoch M, Raychaudhuri A K, Structure and optical properties of Cd-substituted ZnO (Zn_(1-x)Cd_xO) nanostructures synthesized by the high-pressure solution routeNanotechnology 2007 18:115618
[139] Ogawa Y, Fujihara S. Blue Luminescence of MgZnO and CdZnO film deposited at low temperatures. J. Elect. Soc. 2007 154:J283-J288
[140] Van de Walle C G, Neugebauer J. First-principles calculations for defects and impurities: applications to Ill-nitrides. J. Appl. Phys. 2004 95:3851-3879
[141] Mooney P M In: M.Stavola, Editor, Identification of Defects in Semiconductors, Semiconductors and Semimetals vol. 51B, Academic Press, San Diego (1999), p. 93
[142] Hauschild R, Priller H, Decker M, Temperature dependent band gap and homogeneous line broadening of the exciton emission in ZnO. Phys. Status Solidi C 3:976-979
[143] Zhang S B, Wei S H, Zunger A. Intrinsic n-type versus p-type doping asymmetry and the defect physics of ZnO. Phys. Rev. B 2001 63:075203
[144] Oba F, Nishitani S R, Isotani S et al. Energetics of native defects in ZnO. J. Appl. Phys. 2001 90:824
[145] Zhao J L, Zhang W Q, Li X M et al. Convergence of the formation energies of intrinsic point defects in wurtzite ZnO: first-principles study by projector augmented wave method. J. Phys.: Condens. Matter 2006 18:1495-1508
[146] Erhart P, Albe K, Klein A, First-principles study of intrinsic point defects in ZnO: Role of band structure, volume relaxation, and finite-size effectsPhys. Rev. B 2006 73: 205203
[147] Janotti A, Van de Walle C G, Native point defects in ZnO Phys. Rev. B 2007 76:165202
[148] Janotti A, Wei S H, Zhang S B, Donor-donor binding in semiconductors: Engineering shallow donor levels for ZnTe. Appl. Phys. Lett. 2003 83:3522
[149] Hazen R M, Finger L W. High-pressure and high-temperature crystal chemistry of beryllium oxide. J. Appl. Phys. 1986 59:3728
[150] Amrani B, Hassan F E H, Akbarzadeh H. First-principles investigations of ground-and excited-state properties of BeO polymorphs . J. Phys: Condens. Matter 2007 19:6216
[151] Xu Y N, Ching W Y. Electronic, optical, and structural properties of some wurtzite crystals Phys. Rev. B 1993 48:4335
[152] Langer D W, Euwema R N, Era K, Koda T. Spin Exchange in Excitons, the Quasicubic Model and Deformation Potentials in II-VI Compounds. Phys. Rev. B 1970 2:4005-4022
[153] Limpijumnong S, Lambrecht W R L. Theoretical study of the relative stability of wurtzite and rocksalt phases in MgO and GaN. Phys. Rev. B 2001 63:104103
[154] Minemoto T, Negami T, Nishiwaki S et al. Preparation of Zn_(1_x)Mg_xO films by radio frequency magnetron sputtering. Thin solid film 2000 372:173-176
[155] Ann K S, Deutsch T, Yan Y F. Synthesis of band-gap-reduced p-type ZnO films by Cu incorporation. J Appl. Phys. 2007 102:023517
[156] Ahn B D, Kang H S, Kim J H et al. Synthesis and analysis of Ag-doped ZnO. J. Appl. Phys. 2006 100:093701
[157] Wang X B, Li D M, Zeng F et al. Microstructure and properties of Cu-doped ZnO films prepared by dc reactive magnetron sputtering. J. Phys. D: Appl. Phys. 2005 38:4104-4108
[158] Dean J A(Ed.), Lange's Chemistry Handbook, 15~(th) ed. 2005
[159] Werner A, hocheimer. High-pressure x-ray study of Cu_2O and Ag_2O. Phys. Rev. B 1982 25:5929-5934
[160] Martinez-Ruiz A, Moreno M G, Takeuchi N. First principles calculations of the electronic properties of bulk Cu2O, clean and doped with Ag, Ni, and Zn. Solid State Sci. 2003 5:291-295
[161] Ruiz E, Alvarez. Electronic structure and properties of Cu_2O. Phys. Rev. B 197 56:7189-7196
[162] Ching W Y, Xu Y N, Wong K W. Ground-state and optical properties of Cu_2O and CuO ctystal. Phys. Rev. B. 1989 40:7684-7696
[163] Tjeng L H, Meinder M B J, van Elp J et al. Electronic structure of Ag_2O. Phys. Rev. B 1990 41:3190-3199
[164] Yamamoto T, Katayama-Yoshida H. Solution Using a codoping Method to Unipolarity for the Frabrication of p-type ZnO. Jpn. J. Appl. Phys. 1999 38:L166-L169
[165] Tsukazaki A, Saito H, Tamura et al. Systematic examination of carrier polarity in composition spread ZnO thin films codoped with Ga and N. Appl. Phys. Lett. 2002 81:235-237
[166] Nakahara K, Takasu H, Fons P et al. Interactions between gallium and nitrogen dopants in ZnO films grown by radical-source molecular-beam epitaxy. Appl.Phys. Lett. 2001 79:4139-4141
[167] Lu J G, Zhang Y Z, Ye Z Z et al. Low-resistivity, stable p-type ZnO thin films realized using a Li-N dual-acceptor doping method. Appl. Phys. Lett. 2008 88:222114
[168] Zhang Y Z, Lu J G, Ye Z Z et al. Effects of growth temperature on Li-N dual-doped p-type ZnO thin films prepared bu pulsed laser deposition. Appl. Surf. Sci. 2008 254:1993-1996
[169] Sanmyo M, Tomita Y, Kobayashi K. Preparation of p-type ZnO films by doping of Be-N bonds. Chem. Mater. 2003 15:819-821
[170] Sanmyo M, Tomita Y, Kobayashi K. Preparation of Zinc oxide films containing Be and N atoms bu radio frequency magnetron sputtering. Thin Solid Film 2005 472:189-194
[171] Look D C, Reynolds D C, Litton et al. Characterization of homoepitaxial p-type ZnO grown by molecular beam epitaxy. Appl. Phys. Lett. 2002 81:1830-1832
[172] Yan Y F, Zhang S B, Pantelises S T. Control of Doping by Impurity Chemical Potentials: Predictions for p-Type ZnO. Phys. Rev. Lett. 2001 86:5723-5726
[173] Duan X Y, Yao R H, Zhao Y J. The mechanism of Li, N dual-acceptor co-doped p-type ZnO. Appl. Phys. A 2008 91:467-472
[174] Onodera A, Tamaki N, Kawamura Y et al. Dielectric Activity and Ferroelectricity in Piezoelectric Semiconductor Li-Doped ZnO. Jpn. J. Appl. Phys., Part 1 1996 35:5160.
[175] Meyer B K, Alves H, Hofmann D M et al. Bound exciton and donor-acceptor pair recombinations in ZnO. Phys. Status Solidi B 2004 241:231.
[176] Park C H, Zhang S B, Wei S H. Origin of p-type doping difficulty in ZnO: the impurity perspective. Phys. Rev. B 2002 66:073202
[177] Wardle M G, Giss J P, Briddon P R. Theory of Li in ZnO: A limitation for Li-based p-type doping. Phys. Rev. B 2005 71:155205
[178] Kulkarni A J, Zhou M, Sarasamak K et al. Novel Phase Transformation in ZnO Nanowires under Tensile Loading. Phys. Rev. lett. 2006 97:105502
[179] Zhang L X, Huang H C. Structural transformation of ZnO nanostructures. Appl. Phys. Lett. 2007 90:023117
[180] Freeman C L, Claeyssens F, Allan N L et al. Graphitic Nanofilms as Precursors to Wurtzite Films: Theory. Phys. Rev. Lett. 2006 96:066102
[181] Limpijumnong S, Jungthawan S. First-principles study of the wurtzite-to-rocksalt homogeneous transformation in ZnO :A case of a low-transformation barrier. Phys. Rev. B 2004 70:054104
[182] Decremps F, Datchi F, Saitta A M et al. Local structure of condensed zinc oxide. Phys. Rev. B 2003 68:104101
[183] Sun J, Wang H T, He J L et al. Ab initio investigations of optical properties of the high-pressure phases of ZnO. Phys. Rev. B 2005 71:125132
[184] Bates C H. White W B. Science 1962 127:993
[185] Freeouf J L. Far-Ultraviolet Reflectance of II-VI Compounds and Correlation with the Penn—Phillips Gap. Phys. Rev. B 1973 7:3810-3830
[186] Birman J L. Polarization of Fluorescence in CdS and ZnS Single Crystals . Phys. Rev. Lett. 1959 2:157-159
[187] Yu P Y, Cardona M (Ed.) Fundamentals of Semiconductor: Physics and Materials Properties. Springer, Berlin 2001
[188] Qu S W, Zhang Q Y. Interference phenomenon in PL spectra of ZnO thin film.(In prepared)
[2] Bagnall D M, Chen Y F, Zhu Z, et al. Optically pumped lasing of ZnO at room temperature Appl. Phys. Lett., 1997,70:2230-2232.
[3] Miller P M, Jr. in Proc. Intern. Conf. on Semiconducting Materials Reading (1950) (Ed.: H. K. Henisch), Butterworths, London, 1951, p. 172.
[4] Brown H E, Zinc Oxide Rediscovered, The New Jersey Zinc Company,New York, 1957; and Zinc Oxide Properties and Applications, Pergamon, New York, 1976.
[5] Ozgur 0, Alivov Y I, Liu C, et al. A comprehensive review of ZnO materials and devices. J. Appl. Phys., 2005,98:041301-041404.
[6] Jaffe J E and Hess A C. Hartree-Fock study of phase changes in ZnO at high pressure. Phys. Rev. B, 1993,48:7903-7909.
[7] Jaffe J E, Snyder J A, Lin Z, et al. LDA and GGA calculations for high-pressure phase transitions in ZnO and MgO. Phys. Rev. B, 2000,62: 1660-1665.
[8] Boca Raton. CRC Handbook of Chemistry and Physics, 58th ed. CRC Press, 1977.
[9] Dulub O, Boatner L A, Diebold U Surf. Sci., 2002 519:201
[10] Phillips J C, Bonds and Bands in semiconductors.Academic, New York, 1973
[11] Lide D R(Ed,), CRC Handbook of Chemistry and Physics, 73th ed. CRC Press, 1992
[12] Kisi E H, Elcombe, Acta Cryst. 1989 C45:1867
[13] Gerward L, Olsen J S, J. Synchrotron Radiat. 1995 2:233
[14] Bates C H, White W B, and Roy R. New high-pressure polymorph of zinc oxide. Science, 1962, 137: 993-996.
[15] Recio J M, Blanco M A, Luana V et al. Compressibility of the high-pressure rocksalt phase of ZnO. Phys. Rev. B, 1998, 58: 8949-8954
[16] Jamieson J C, Phys. Earth Planet. Inter. 1970,3:201
[17] Desgreniers S. Structural and compressive parameters High-density phases of ZnO: Phys. Rev. B 1998 58:14102-14105
[18] Chen M, Wang X, Yu YH, et al. X-ray photoelectron spectroscopy and auger electron spectroscopy studies of Al-doped ZnO films. Appl. Surf. Sci., 2000,158(1-2):134-140.
[19] Minami T, Sato H, Nanto et al., Heat treatment in hydrogen gas and plasma for transparent conducting oxide films such as ZnO, SnO_2 and indium tin oxide. Thin Solid films, 1989,176:277-281.
[20] Klingshirn C. Semiconductor Optics, 3rd ed., Springer, Heidelberg, 2006
[21] Rossler U (ED.) Landolt-Bornstein, New Series, Group III, Vol. 17 B, 22, 41B, Springer, Heidelberg, 1999.
[22] Osinsky A, Dong J W, Kauser, et al. MgZnO/AlGaN heterostructure light-emitting diodes. Appl. Phys. Lett., 2004,85: 4272-4274
[23] Liu Y, Gorla C R, Liang S, et al. Ultraviolet detectors based on epitaxial ZnO films grown by MOCVD, J Elec Mater, 2000,29(1): 69-74.
[24] Look D C, Reynolds D C, Hemsky J M., Production and annealing of electron irradiation damage in ZnO. Appl.Phys.Lett., 1999, 75(6):811-813.
[25] Hoffman R L, ZnO-channel thin-film transistors: Channel mobility J. Appl. Phys. 2004,95:5813-5819
[26] Fortunato E M C, Barquinha P M C, Pimental A C M P G, et al. Fully Transparent ZnO Thin-Film Transistor Produced at Room Temperature, Adv. Mater. 2005,17:590-594
[27] Wang H T, Rang B S, Ren F et al. Hydrogen-selective sensing at room temperature with ZnO nanorods. Appl. Phys. Lett. 2005 86:243503-243505
[28] Pearton S J, Heo W H, Norton D P, et al. Dilute magnetic semiconducting oxides. 2004 19:R59-R74
[29] Bertram F, Giemsch S, Fortser et al. Direct imaging of phase separation in ZnCdO layers. Appl. Phys. Lett. ,2006 88:061915
[30] Sakurai K, Takagi T, Kubo T et al. Spatial composition fluctuations in blue-luminescent ZnCdO semiconductor films grown by molecular beam epitaxy. J. Crys. Grow. 2002 237-239:514-517
[31] Ma D W, Ye Z Z, Chen L L. Dependence of structural and optical properties of Znl-xCdxO films on the Cd composition. Phys. Status Solidi (a) 2004 201:2929-2933
[32] Makino T, Segawa Y, Kawasaki M, et al, Band gap engineering based on Mg_xZn_(1-x)O and Cd_yZn_(1-y)O ternary alloy films,, Appl. Phys. Lett., 200178:1237-1239
[33] Ohtomo A, Kawasaki M, Koida T, et al, Mg_xZn_(1-x)O as a II -VI widegap semiconductor alloy, Appl. Phys. Lett., 1998 72:2466-2468.
[34] Choopun S, Vispute R D, Yang W, et al, Realization of band gap above 5.0 eV in metastable cubic-phase MgxZnl-xO alloy films,, Appl. Phys. Lett., 2002 80:1529-1531.
[35] Chen J, Shen W Z, Long-wavelength optical phonon properties of ternary MgZnO thin films, Appl. Phys. Lett., 2003 83:2154-2156.
[36] Ryu Y R, Lee T S, Lubguban J A, et al. Wide-band gap oxide alloy: BeZnO Appl. Phys . Lett. 2006 88:052103.
[37] Ryu Y R, Lee T S, Lubguban J A, et al. Next generation of oxide photonic devices: ZnO-based ultraviolet light emitting diodes. Appl. Phys . Lett. 2006 88:241108
[38] Service R F. Will UV lasers beat the blues?. Science, 1997,276(5314): 895.
[39] Kohan A F, Ceder G, Morgan D, et al. First-principle study of point defects in ZnO. Phys. Rev. B 2000 61:15019-15027
[40] Van de Walle C G.. Hydrogen as a Cause of Doping in Zinc Oxide. Phys. Rev. Lett. 2000 85:1012-1015
[41] Myong D Y, Baik D J, Lee C H, et al. Extremely Transparent and Conductive ZnO:Al Thin Films Prepared by Photo-Assisted Metalorganic Chemical Vapor Deposition (photo-MOCVD) Using AlCl_3(6H_2O) as New Doping Material. Jpn. J. Appl. Phys., Part 2 2007 36:L1078-L1081
[42] Ataev B M, Bagamadova A M, Djabrailov A M, et al. Highly conductive and transparent Ga-doped epitaxial ZnO films on sapphire by CVD. Thin Solid Film 1995 260:19-20
[43] Van der Walle C G, Laks D B, Neumark G F, et al. First-principles calculations of solubilities and doping limits: Li, Na, and N in ZnSe. Phys. Rev. B 1993 47:9425-9434
[44] Look D C, Jones R L, Sizelove J R, et al. The path to ZnO devices: donor and acceptor dynamics. Physica Status Solidi (a) 2003 195:171-177
[45] Park C H, Zhang S B, Wei S H. Origin of p-type doping difficulty in ZnO: The impurity perspective. Phys. Rev. B 2002 67:073202
[46] Ahn B D, Kang H S, im J H, et al. Synthesis and analysis of Ag-doped ZnO. J. Appl. Phys. 2006 100:093701
[47] Ahn B D, Deutsch T, Tan T F, et al. Synthesis of band-gap-reduced p-type ZnO films by Cu incorporation. J. Appl. Phys. 2007 102:023517
[48] Kobayashi A, Sankey O F, Dow J D, et al. Deep energy levels of defects in the wurtzite semiconductors AIN, CdS, CdSe, ZnS, and ZnO. Phys. Rev. B 1983 28:946-956
[49] Wu Z L, Merz J L, Werkhoven C J, et al. Shallow N acceptor in N+-implanted ZnSe. Appl. Phys. Lett. 1982 40:345-347
[50] Iwata K, Fons P, Yamada A, et al. Nitrogen-induced defects in ZnO: N grown on sapphire substrate by gas source MBE. J. Cryst. Growth 2000 209:526-531
[51] Look D C, Reynolds D C, Litton C W, et al. Characterization of homoepitaxial p-type ZnO grown by molecular beam epitaxy. Appl. Phys. Lett. 2002 81:1830-1832
[52] Ashrafi A B M A, Suemune I, Kumano H, et al. Nitrogen-Doped p-Type ZnO Layers Prepared with H2O Vapor-Assisted Metalorganic Molecular-Beam Epitaxy. Jpn. J. Appl. Phys. 2002 41:L1281-L1284
[53] Vaithianathan V, Lee B T, Chang C H, et al. Characterization of As-doped, p-type ZnO by x-ray absorption near-edge structure spectroscopy. Appl. Phys. Lett. 2006 88:112103
[54] Vaithianathan V, Lee B T, Kim S S, Preparation of As-doped p-type ZnO films using a Zn3As2 /ZnO target with pulsed laser deposition. Appl. Phys. Lett. 2005 86:062101
[55] Aoki T, Hatanaka Y, Look D C. ZnO diode fabricate by excimer-laer doping Appl. Phys. Lett. 2000 76:3257-3259
[56] Jaffe J E, Snyder J A, Lin Z, et al. LDA and GGA calculations for high-pressure phase transitions in ZnO and MgO. Phys. Rev. B, 2000, 62: 1660-1665.
[57] Nishidate K, Yoshizawa M, Hasegawa M. Energetics of Mg and B adsorption on polar zinc oxide surfaces from first principles. Phys. Rev. B, 2008, 77:035330
[58] Fan W, Xu H, Rosa A L, et al. First-principles calculations of reconstructed [0001] ZnO nanowires. Phys. Rev. B, 2007,76: 073302.
[59] Chanier T, Opahle I, Sargolzaei M, et al. Magnetic State around Cation Vacancies in II—VI Semiconductors. Phys. Rev. Lett. 2008 100:026405
[60] Fan X F, Zhu Z X, Ong Y S, et al. A direct first principles study on the structure and electronic properties of Be_xZn_(1-x)O. Appl. Phys. Lett. 2007 91:121121.
[61] Ding S F, Fan G H, Li S T, et al. Theoretical study of Be_xZn_(1-x)O alloys. Physica B 2007 394:127-131.
[62] Fan X F, Sun H D, Shen Z X, et al. A first-principle analysis on the phase stabilities, chemical bonds and band gaps of wurtzite structure A_xZn_(1-x)O alloys (A = Ca, Cd, Mg) J. Phys.: Condens. Matter 2008 20:235221
[63] Gopal P, Spaldin N A. Magnetic interactions in transition-metal-doped ZnO: An ab initio study. Phys. Rev. B 2006 74:094418
[64] Patterson C H. Role of defects in ferromagnetism in Zn_(1-x)Co_xO: A hybrid density-functional study. Phys. Rev. B 2006 74:144432
[65] Debermardi A, Fanciulli M. Ab initio study of magnetic interaction of Fe doped ZnO with intrinsic vacancies. Appl. Phys. Lett. 207 90: 212510.
[66] Minegishi, K., Koiwai, Y., Kikuchi Y. et al. Growth of p-type zinc oxide films by chemical vapor deposition. Jpn. J. Appl. Phys., Part 2:Letters, 1997,36 (11 PART A): L1453-L1455.
[67] Zhang S B, Northrup J E. Chemical potential dependence of defect formation energies in GaAs: Application to Ga self-diffusion. Phys. Rev. Lett. 1991 67:2339-2342
[68] Laks D B, Van der Walle C G, Neumark G F, et al. Native defects and self-compensation in ZnSe. Phys. Rev. B 1992 45:10965
[69] Wei S H. Overcoming the doping bottleneck in semiconductors. Comp. Mater. Sci. 2004 30:337-348
[70] Van der Walle, C G, Neugebauer J. First-principles calculations for defects and impurities: Applications to III-nitrides. J Appl. Phys. 2004 95:3851-3879
[71] Yan Y F, Zhang S B, Panteldes. Control of doping by Impurity Chemical Potential: Predictions for p-type ZnO Phys. Rev. Lett. 2001 86:5723-5726
[72] Yan Y F, Al-Jassim M M, Wei S H. Doping of ZnO by group-IB elements. Appl. Phys. Lett. 2006 89:181912
[73] Limpijumnong S, Zhang S B, Wei S H, et al. Doping by Large-Size-Mismatched Impurities: The Microscopic Origin of Arsenicor Antimony-Doped p-Type Zinc Oxide. Phys. Rev. Lett. 2004 92:155504
[74] Park C H, Zhang S B, Wei S H. Origin of p-type doping difficulty in ZnO: The impurity perspective. Phys. Rev. B 2002 66:073202
[75] Li J B, Wei S H, Li S S, et al. Design of shallow acceptors in ZnO: First-principles band-structure calculations. Phys. Rev. B 2006 74:081201
[76] Yan Y F, Li J B, Wei S H, et al Possible Approach to Overcome the Doping Asymmetry in Wideband Gap Semiconductors. Phys. Rev. Lett. 2007 98:135506
[77] The 1998 Nobel Prize in chemisty: heep://www.nobel.se/chemistry/laureates/1998/; also see: Kohn W, Rev. Mod. Phys. 71 (1999) 1253
[78] Born M, Oppenheimer R, ZUT quantentheorie der Molekeln. Ann. Phys. 1927, 84:457-484
[79] Hartree D R, Proc. Cam. Phil. Soc. 24 (1928) 89
[80] Szabo A, Ostlun N S, Modern quantum chemistry - introduction to advance electronic structure theory. New York: McGraw-Hill 1989
[81] Fock V, Z. Phys. 61 (1930) 209
[82] Slater J C, Quantum Theory of Atomic Structure, New York, McGraw-Hill, 1960
[83] Hohenberg P, Kohn W. Inhomogeneous electron gas. Phys. Rev. 1964,136: B864-871
[84] Kohn W, Sham L J. Selfe-consistant equations including exchange ang correlation effects. Phys. Rev. 1965, 140:A1133-1138
[85]Janak J F. Proof that (?)E/(?)ni=ε in density-functional theory. Phys. Rev. B 1978 18: 7165-7168
[86] Hedin L and Lundqvist B I. Explicit local exchange-correlation potentials. J. Phys. C: solid state phys. 19714:2064-2083
[87] Ceperley D M and Alder B J. Ground State of the Electron Gas by a Stochastic Method. Phys. Rev. Lett. 1980 45,566-569
[88] Perdew J P, Zunger A. Self-interaction correction to density-functional approximations for many-electron systems. Phys. Rev. B 1981 23: 2048-6079
[89] Perdew J P, Wang Y. Accurate and simple analytic representation of the electron-gas correlation energy. Phys. Rev. B. 1992 45:13244-13249
[90] Harris J, Jones R O. The surface energy of a bounded electron gas. J. Phys. F 1974 4:1170-1186
[91] Gunnarsson O, Lundqvist B I. Exchange and correlation in atoms, molecules, and solids by the spin-density-functional formalism. Phys. Rev. B 1976 13:4274-4298
[92] Langreth D C, Perdew J P. Exchange-correlation energy of a metallic surface: Wave-vector analysis. Phys. Rev. B 15:2884-2901
[93] Langreth D C, Mehl M J. Easily Implementable Nonlocal Exchange-Correlation Energy Functional. Phys. Rev. Lett. 1981 47:446-450
[94] Perdew J P, Chevary J A, Vosko S H, Jaekson K A, Singh D J, Fiolhais C. Atoms, molecules, solids. and surface: Applications of the generalized gradient approximation of exchange and correlation. Phys. Rev. B 1992 46:6671-6687
[95] Perdew J P, Wang Y. Accurate and simple density functional for the electronic exchange energy: Generalized gradient approximation. Phys. Rev. B 1986 33: 8800-8802
[96] Perdew J P. Density-functional approximation for the correlation energy of the inhomogeneous electron gas. 1986 Phys. Rev. B 33:8822-8824
[97] Perdew J P, Wang Y. Accurate and simple analytic representation of the electron-gas correlation energy. Phys. Rev. B 1992 45: 13244-13249
[98] Perdew J P, Burke K, Ernzerhof M. Generalized Gradient Approximation Made Simple. Phys. Rev. Lett. 1996 77:3865-3868
[99] Perdew J P, Burke K, Ernzerhof M. Generalized Gradient Approximation Made Simple. Phys. Rev. Lett. 1996 78: 1396-1397 (Erratum)
[100] Lieb E H, Oxford S. Int. J. Quantumn Chem. 1981 19:427
[101] Becke A D. Density-functional exchange-energy approximation with correct asymptotic behavior. Phys.Rev. A 1988 38:3098-3100
[102] Lee C, Yang W, Parr R G. Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density. Phys. Rev. B 1988 37: 785-789
[103] Ashcroft N W, Mermin N D. Solid State Physics. Philadelphia, Holt Sauders, 1976, p113
[104] Monkhorst H J, Pack J D. Special points for Brillouin-zone integrations, Phys. Rev. B, 1976 13: 5188-5192.
[105] Monkhorst H J, Pack J D. Special points for Brillouin-zone integrations - a reply, Phys. Rev. B, 1977 1:1748-1749
[106] Robertson I J, Payne M C. k-point sampling and the k.p method in pseudopotential total energy calculations. J. Phys.: Condens. Matter 1990 2:9837-9852
[107] Robertson I J, Payne M C. The k.p method in pseudopotential total energy calculations: error reduction and absolute energies. J. Phys.: Condens. Matter 1991 3: 8841-8853
[108] Phillpe J C. Energy-Band Interpolation Scheme Based on a Pseudopotential. Phys. Rev. 1958 112: 685-695
[109] Cohen M L and Heine. The fitting of pseudopotentials to experimental data and their subsequent application, in Solid State Physics, Vol. 24, eds. H. Ehrenreich, F. Seitz, and D. Turnbull (Academic Press, New York, 1970), p.37.
[110] Yin M T and Cohen M L. Theory of ab initio pseudopotential calculations Phys. Rev. B 1982 25: 7403-7412
[111] Vanderbilt D, Soft self-consistent pseudopotentials in generalized eigenvalue formalism. Phys. Rev. B 1990 41:7892-7895
[112] Blochl P E, Projector augmented-wave method. Phys. Rev. B 1994 50: 17953-17979
[113] Kresse G, Joubert D, From ultrasoft pseudopotentials to the projector augmented-wave method. Phys. Rev. B 1999 59:1758-1775
[114] Rappe A K, Rabe K, Kaxiras E, Joannopolous J D, Optimized pseudopotentials, Phys. Rev. B 1990 41:1227-1230
[115] Lin J S, Qteish A, Payne M C, Heine V, Optimized and transferable nonlocal separable ab initio pseudopotentials, Phys. Rev. B 1993 47:4174-4180
[116] Keinmann L, Bylander D M Phys. Efficacious Form for Model Pseudopotentials, Rev. Lett 1982 48: 1425-1428
[117] King-Simth R D, Payne M C lin J S Real-space implementation of nonlocal pseudopotentials for first-principles total-energy calculations, Phys. Rev. B 1991 44: 13063-13066
[118] Kresse G Fuhrtmuller J, Efficient iterative schemes for ab initio total energy calculations using a plane-wave basis set. Phys. Rev. B 1996 54: 11169-11186
[119] Kresse G Fuhrtmuller J, Efficiency of ab initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comp. Mat. Sci. 1996 6: 15-50
[120] Decremps F, Dathi F, Poloan A, et al. Local structure of condensed zin oxide. Phys. Rev. B 2003 68:104101
[121] Schleife A, Fuchs F, Furthmuller J, et al. First-principles study of ground- and excited-state properties of MgO, ZnO, and CdO polymorphs. Phys. Rev. B 2006 73:245212
[122] Jaffe E, Snydern J A, Lin Z. et al. LDA and GGA calculations for high-pressure phase transitions in ZnO and MgO. Phys. Rev. B 2000 62:1660-1665
[123] Guerrero-Moreno R J, Takeuchi N. First principles calculations of the ground-state properties and structural phase transformation in CdO. Phys. Rev. B 2002 66:205205
[124] Janotti A, Segev D and Van der Walle C G. Effects of cation d states on the structural and electronic properties of Ill-nitride and H-oxide wide-band-gap semiconductors. Phys. Rev. B 2007 74:045202
[125] Vladimir I A, Aryasetiawan F and Lichtenstein A I. First-principles calculations of the electronic structure and spectra of strongly correlated systems: the LDA+ U method. J. phys. Condens. Mater. 1997 9:767-808
[126] Osuch K, Lombardi E B, Gebicki W. First principles study of ferromagnetism in Ti_(0.0625)Zn_(0.9357)O. Phys. Rev. B 2006 73:075202
[127] Moon C Y, Wei S H, Zhu Y Z, et al. Band-gap bowing coefficients in large size-mismatched II-VI alloys: first-principles calculations. Phys. Rev. B 2006 74:233202.
[128] Sun C W, Xin P, Ma C Y et al. Optical and electrical properties of Cd_xZn_(1-x)O films grown on Si substrates by reactive radio-frequency magnetron sputtering. Appl. Phys. Lett. 2006 89:181923
[129] Persson C. Strong Valence-Band Offset Bowing of ZnO_(1_x)S_X Enhances p-Type Nitrogen Doping of ZnO-like Alloys. Phys. Phys. Lett. 2006 97:146403
[130] Zhang X D, Guo M L, Li W X et al. First-principle study of electronic and optical properties in wurtzite Cd_xZn_(1-x)O. J. Appl. Phys. 2008 103:063721
[131] Zuniga-Pérez J, Munoz-Sanjose V, Lorenz M, et al., G. Benndort, S. Heitsch, D. Spemann, and M. Grundmann, Structural characterization of a-plane Zn_(1-x)Cd_xO (0≤x≤0.085) thin films grown by metal-organic vapor phase epitaxy. J. Appl. Phys. 2006 99:023514
[132] Ishihara J, Nakamura A, Shigemori S, et al. Zn_(1-x)Cd_xO systems with visible band gap. Appl. Phys. Lett. 2006 89:091914.
[133] Delley B. From molecular to solid with the DMol3 approach. J. Chem. Phys. 2000 113:7756
[134] Janotti A, Van der Walle C G. Absolute deformation potentials and band alignment of wurtzite ZnO, MgO, and CdO. Phys. Rev. B 2007 75:121201
[135] Wei S H, Zunger A. Role of metal d states in II-VI semiconductors. Phys. Rev. B 1988 37:8958-8981
[136] Wei S H, Zunger A. Calculated natural band offsets of all II-VI and III—V semiconductors: Chemical trends and the role of cation d orbitals Appl. Phys. Lett. 1998 72:2011
[137] Ma D W, Ye Z Z, Chen L L. Dependence of structural and optical properties of Zn_(1-x)Cd_xO films on the Cd compositionPhys. Status Solidi A 2004 201:2929
[138] Ghoch M, Raychaudhuri A K, Structure and optical properties of Cd-substituted ZnO (Zn_(1-x)Cd_xO) nanostructures synthesized by the high-pressure solution routeNanotechnology 2007 18:115618
[139] Ogawa Y, Fujihara S. Blue Luminescence of MgZnO and CdZnO film deposited at low temperatures. J. Elect. Soc. 2007 154:J283-J288
[140] Van de Walle C G, Neugebauer J. First-principles calculations for defects and impurities: applications to Ill-nitrides. J. Appl. Phys. 2004 95:3851-3879
[141] Mooney P M In: M.Stavola, Editor, Identification of Defects in Semiconductors, Semiconductors and Semimetals vol. 51B, Academic Press, San Diego (1999), p. 93
[142] Hauschild R, Priller H, Decker M, Temperature dependent band gap and homogeneous line broadening of the exciton emission in ZnO. Phys. Status Solidi C 3:976-979
[143] Zhang S B, Wei S H, Zunger A. Intrinsic n-type versus p-type doping asymmetry and the defect physics of ZnO. Phys. Rev. B 2001 63:075203
[144] Oba F, Nishitani S R, Isotani S et al. Energetics of native defects in ZnO. J. Appl. Phys. 2001 90:824
[145] Zhao J L, Zhang W Q, Li X M et al. Convergence of the formation energies of intrinsic point defects in wurtzite ZnO: first-principles study by projector augmented wave method. J. Phys.: Condens. Matter 2006 18:1495-1508
[146] Erhart P, Albe K, Klein A, First-principles study of intrinsic point defects in ZnO: Role of band structure, volume relaxation, and finite-size effectsPhys. Rev. B 2006 73: 205203
[147] Janotti A, Van de Walle C G, Native point defects in ZnO Phys. Rev. B 2007 76:165202
[148] Janotti A, Wei S H, Zhang S B, Donor-donor binding in semiconductors: Engineering shallow donor levels for ZnTe. Appl. Phys. Lett. 2003 83:3522
[149] Hazen R M, Finger L W. High-pressure and high-temperature crystal chemistry of beryllium oxide. J. Appl. Phys. 1986 59:3728
[150] Amrani B, Hassan F E H, Akbarzadeh H. First-principles investigations of ground-and excited-state properties of BeO polymorphs . J. Phys: Condens. Matter 2007 19:6216
[151] Xu Y N, Ching W Y. Electronic, optical, and structural properties of some wurtzite crystals Phys. Rev. B 1993 48:4335
[152] Langer D W, Euwema R N, Era K, Koda T. Spin Exchange in Excitons, the Quasicubic Model and Deformation Potentials in II-VI Compounds. Phys. Rev. B 1970 2:4005-4022
[153] Limpijumnong S, Lambrecht W R L. Theoretical study of the relative stability of wurtzite and rocksalt phases in MgO and GaN. Phys. Rev. B 2001 63:104103
[154] Minemoto T, Negami T, Nishiwaki S et al. Preparation of Zn_(1_x)Mg_xO films by radio frequency magnetron sputtering. Thin solid film 2000 372:173-176
[155] Ann K S, Deutsch T, Yan Y F. Synthesis of band-gap-reduced p-type ZnO films by Cu incorporation. J Appl. Phys. 2007 102:023517
[156] Ahn B D, Kang H S, Kim J H et al. Synthesis and analysis of Ag-doped ZnO. J. Appl. Phys. 2006 100:093701
[157] Wang X B, Li D M, Zeng F et al. Microstructure and properties of Cu-doped ZnO films prepared by dc reactive magnetron sputtering. J. Phys. D: Appl. Phys. 2005 38:4104-4108
[158] Dean J A(Ed.), Lange's Chemistry Handbook, 15~(th) ed. 2005
[159] Werner A, hocheimer. High-pressure x-ray study of Cu_2O and Ag_2O. Phys. Rev. B 1982 25:5929-5934
[160] Martinez-Ruiz A, Moreno M G, Takeuchi N. First principles calculations of the electronic properties of bulk Cu2O, clean and doped with Ag, Ni, and Zn. Solid State Sci. 2003 5:291-295
[161] Ruiz E, Alvarez. Electronic structure and properties of Cu_2O. Phys. Rev. B 197 56:7189-7196
[162] Ching W Y, Xu Y N, Wong K W. Ground-state and optical properties of Cu_2O and CuO ctystal. Phys. Rev. B. 1989 40:7684-7696
[163] Tjeng L H, Meinder M B J, van Elp J et al. Electronic structure of Ag_2O. Phys. Rev. B 1990 41:3190-3199
[164] Yamamoto T, Katayama-Yoshida H. Solution Using a codoping Method to Unipolarity for the Frabrication of p-type ZnO. Jpn. J. Appl. Phys. 1999 38:L166-L169
[165] Tsukazaki A, Saito H, Tamura et al. Systematic examination of carrier polarity in composition spread ZnO thin films codoped with Ga and N. Appl. Phys. Lett. 2002 81:235-237
[166] Nakahara K, Takasu H, Fons P et al. Interactions between gallium and nitrogen dopants in ZnO films grown by radical-source molecular-beam epitaxy. Appl.Phys. Lett. 2001 79:4139-4141
[167] Lu J G, Zhang Y Z, Ye Z Z et al. Low-resistivity, stable p-type ZnO thin films realized using a Li-N dual-acceptor doping method. Appl. Phys. Lett. 2008 88:222114
[168] Zhang Y Z, Lu J G, Ye Z Z et al. Effects of growth temperature on Li-N dual-doped p-type ZnO thin films prepared bu pulsed laser deposition. Appl. Surf. Sci. 2008 254:1993-1996
[169] Sanmyo M, Tomita Y, Kobayashi K. Preparation of p-type ZnO films by doping of Be-N bonds. Chem. Mater. 2003 15:819-821
[170] Sanmyo M, Tomita Y, Kobayashi K. Preparation of Zinc oxide films containing Be and N atoms bu radio frequency magnetron sputtering. Thin Solid Film 2005 472:189-194
[171] Look D C, Reynolds D C, Litton et al. Characterization of homoepitaxial p-type ZnO grown by molecular beam epitaxy. Appl. Phys. Lett. 2002 81:1830-1832
[172] Yan Y F, Zhang S B, Pantelises S T. Control of Doping by Impurity Chemical Potentials: Predictions for p-Type ZnO. Phys. Rev. Lett. 2001 86:5723-5726
[173] Duan X Y, Yao R H, Zhao Y J. The mechanism of Li, N dual-acceptor co-doped p-type ZnO. Appl. Phys. A 2008 91:467-472
[174] Onodera A, Tamaki N, Kawamura Y et al. Dielectric Activity and Ferroelectricity in Piezoelectric Semiconductor Li-Doped ZnO. Jpn. J. Appl. Phys., Part 1 1996 35:5160.
[175] Meyer B K, Alves H, Hofmann D M et al. Bound exciton and donor-acceptor pair recombinations in ZnO. Phys. Status Solidi B 2004 241:231.
[176] Park C H, Zhang S B, Wei S H. Origin of p-type doping difficulty in ZnO: the impurity perspective. Phys. Rev. B 2002 66:073202
[177] Wardle M G, Giss J P, Briddon P R. Theory of Li in ZnO: A limitation for Li-based p-type doping. Phys. Rev. B 2005 71:155205
[178] Kulkarni A J, Zhou M, Sarasamak K et al. Novel Phase Transformation in ZnO Nanowires under Tensile Loading. Phys. Rev. lett. 2006 97:105502
[179] Zhang L X, Huang H C. Structural transformation of ZnO nanostructures. Appl. Phys. Lett. 2007 90:023117
[180] Freeman C L, Claeyssens F, Allan N L et al. Graphitic Nanofilms as Precursors to Wurtzite Films: Theory. Phys. Rev. Lett. 2006 96:066102
[181] Limpijumnong S, Jungthawan S. First-principles study of the wurtzite-to-rocksalt homogeneous transformation in ZnO :A case of a low-transformation barrier. Phys. Rev. B 2004 70:054104
[182] Decremps F, Datchi F, Saitta A M et al. Local structure of condensed zinc oxide. Phys. Rev. B 2003 68:104101
[183] Sun J, Wang H T, He J L et al. Ab initio investigations of optical properties of the high-pressure phases of ZnO. Phys. Rev. B 2005 71:125132
[184] Bates C H. White W B. Science 1962 127:993
[185] Freeouf J L. Far-Ultraviolet Reflectance of II-VI Compounds and Correlation with the Penn—Phillips Gap. Phys. Rev. B 1973 7:3810-3830
[186] Birman J L. Polarization of Fluorescence in CdS and ZnS Single Crystals . Phys. Rev. Lett. 1959 2:157-159
[187] Yu P Y, Cardona M (Ed.) Fundamentals of Semiconductor: Physics and Materials Properties. Springer, Berlin 2001
[188] Qu S W, Zhang Q Y. Interference phenomenon in PL spectra of ZnO thin film.(In prepared)
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