Evolution Pathway of CIGSe Nanocrystals for Solar Cell Applications

详细信息    查看全文

• 作者：Mahshid Ahmadi ; Stevin Snellius Pramana ; Lifei Xi ; Chris Boothroyd ; Yeng Ming Lam ; Subodh Mhaisalkar
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：April 12, 2012
• 年：2012
• 卷：116
• 期：14
• 页码：8202-8209
• 全文大小：501K
• 年卷期：v.116,no.14(April 12, 2012)
• ISSN：1932-7455

文摘

CuIn_xGa_1鈥?i>xSe₂ nanocrystals synthesized via the hot injection route have been used to make thin film solar cells with high power conversion efficiency. Thus, CuIn_xGa_1鈥?i>xSe₂ nanocrystals have the potential to provide a low cost and high efficiency solution to harvest solar energy. Stoichiometry control of these nanocrystals offers the possibility of tuning the band gap of this material. It is important to understand how the composition of quaternary CuIn_xGa_1鈥?i>xSe₂ nanocrystals evolves to control the stoichiometry of this compound. We report a systematic study of the growth and evolution pathways of quaternary CuIn_0.5Ga_0.5Se₂ nanocrystals in a hot coordination solvent. The reaction starts by the formation of a mixture of binary and ternary nanocrystals, which transforms subsequently to CuIn_0.5Ga_0.5Se₂ nanocrystals. These binary and ternary compounds dissolve in the course of the reaction, so as to provide the molecular precursor for monophasic CuIn_0.5Ga_0.5Se₂ nanocrystals to form. Here, we study the growth sequence of these spherical, monophasic CuIn_0.5Ga_0.5Se₂ nanocrystals as a function of time. Control experiments indicated that the phase changes of CuIn_0.5Ga_0.5Se₂ nanocrystals are temperature- and time-dependent. The change in the stoichiometry of CuIn_0.5Ga_0.5Se₂ during growth was estimated using Vegard鈥檚 law.