Luminescence Properties of SrZrO3/Tb3+ Perovskite: Host-Dopant Energy-Transfer Dynamics and Local Structure of Tb3+

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• 作者：Santosh Kumar Gupta ; Partha Sarathi Ghosh ; Ashok Kumar Yadav ; Nimai Pathak ; Ashok Arya ; Shambhu Nath Jha ; Dibyendu Bhattacharyya ; Ramakant Mahadeo Kadam
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：February 15, 2016
• 年：2016
• 卷：55
• 期：4
• 页码：1728-1740
• 全文大小：788K
• ISSN：1520-510X

文摘

SrZrO<sub>3sub> perovskite (SZP) was synthesized using gel-combustion route and characterized systematically using X-ray diffraction and time-resolved photoluminescence techniques. A detailed analysis of the optical properties of Tb<sup>3+sup> ions in SrZrO<sub>3sub> was performed to correlate them with the local environment of the lanthanide ions in this perovskite. Photoluminescence (PL) spectroscopy showed that emission spectrum consists of host as well as Tb<sup>3+sup> emission indicating the absence of complete host-dopant energy transfer. On the basis of emission spectrum and PL decay study it was also observed that Tb<sup>3+sup> is not homogeneously distributed in SrZrO<sub>3sub> perovskite; rather, it is occupying two different sites. It is corroborated using extended X-ray absorption fine structure studies that Tb<sup>3+sup> is stabilized on both six-coordinated Zr<sup>4+sup> and eight-coordinated Sr<sup>2sup> site. The energies calculated using density functional theory (DFT) indicates that Tb occupation in Sr site is energetically more favorable than Zr site. The analysis of valence charge distribution also substantiated our structural stability analysis of site-selective Tb doping in SrZrO<sub>3sub>. Time-resolved emission spectroscopy is employed to elucidate the difference in the spectral feature of Tb<sup>3+sup> ion at Sr<sup>2+sup> and Zr<sup>4+sup> site. DFT-calculated density of states analysis showed that energy mismatch of Tb-d states with Zr-d and O-p states of SZP makes the energy transfer from host SZP to Tb<sup>3+sup> ion difficult.