Eu3+-Doped Wide Band Gap Zn2SnO4 Semiconductor Nanoparticles: Structure and Luminescence

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• 作者：Mirjana Dimitrievska ; Tamara B. Ivetić ; Alexander P. Litvinchuk ; Andrew Fairbrother ; Bojan B. Miljević ; Goran R. Štrbac ; Alejandro Pérez Rodríguez ; Svetlana R. Lukić-Petrović
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：August 25, 2016
• 年：2016
• 卷：120
• 期：33
• 页码：18887-18894
• 全文大小：543K
• 年卷期：0
• ISSN：1932-7455

文摘

Nanocrystalline Zn<sub>2sub>SnO<sub>4sub> powders doped with Eu<sup>3+sup> ions were synthesized via a mechanochemical solid-state reaction method followed by postannealing in air at 1200 °C. X-ray diffraction (XRD), energy-dispersive X-ray (EDX), and Raman and photoluminescence (PL) spectroscopies provide convincing evidence for the incorporation of Eu<sup>3+sup> ions into the host matrix on noncentrosymmetric sites of the cubic inverse spinel lattice. Microstructural analysis shows that the crystalline grain size decreases with the addition of Eu<sup>3+sup>. Formation of a nanocrystalline Eu<sub>2sub>Sn<sub>2sub>O<sub>7sub> secondary phase is also observed. Luminescence spectra of Eu<sup>3+sup>-doped samples show several emissions, including narrow-band magnetic dipole emission at 595 nm and electric dipole emission at 615 nm of the Eu<sup>3+sup> ions. Excitation spectra and lifetime measurements suggest that Eu<sup>3+sup> ions are incorporated at only one symmetry site. According to the crystal field theory, it is assumed that Eu<sup>3+sup> ions participate at octahedral sites of Zn<sup>2+sup> or Sn<sup>4+sup> under a weak crystal field, rather than at the tetrahedral sites of Zn<sup>2+sup>, because of the high octahedral stabilization energy for Eu<sup>3+sup>. Activation of symmetry forbidden (IR-active and silent) modes is observed in the Raman scattering spectra of both pure and doped samples, indicating a disorder of the cation sublattice of Zn<sub>2sub>SnO<sub>4sub> nanocrystallites. These results were further supported by the first principle lattice dynamics calculations. The spinel-type Zn<sub>2sub>SnO<sub>4sub> shows effectiveness in hosting Eu<sup>3+sup> ions, which could be used as a prospective green/red emitter. This work also illustrates how sustainable and simple preparation methods could be used for effective engineering of material properties.