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 Zn₂SnO₄ powders doped with Eu³⁺ 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 Eu³⁺ 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 Eu³⁺. Formation of a nanocrystalline Eu₂Sn₂O₇ secondary phase is also observed. Luminescence spectra of Eu³⁺-doped samples show several emissions, including narrow-band magnetic dipole emission at 595 nm and electric dipole emission at 615 nm of the Eu³⁺ ions. Excitation spectra and lifetime measurements suggest that Eu³⁺ ions are incorporated at only one symmetry site. According to the crystal field theory, it is assumed that Eu³⁺ ions participate at octahedral sites of Zn²⁺ or Sn⁴⁺ under a weak crystal field, rather than at the tetrahedral sites of Zn²⁺, because of the high octahedral stabilization energy for Eu³⁺. 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 Zn₂SnO₄ nanocrystallites. These results were further supported by the first principle lattice dynamics calculations. The spinel-type Zn₂SnO₄ shows effectiveness in hosting Eu³⁺ 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.