Site-Selective Doping and Site-Sensitive Photoluminescence of Eu3+ and Tb3+ in Perovskite-Type LaLuO3.

Abstract

Eu3+ and Tb3+ ions were site-selectively doped into LaLuO3 with the orthorhombic perovskite-type structure (ABO3), and their luminescence properties were examined considering the doping sites (A or B sites). The X-ray diffraction analysis revealed the expansion or contraction of the unit cell volumes of the materials depending on the doping sites. The spectra of X-ray absorption near edge structure for the Eu and Tb LIII edge exhibited different shapes for the ions at A and B sites, confirming the site-selective doping of Eu3+ and Tb3+ in LaLuO3. The photoluminescence (PL) and PL excitation (PLE) spectra of the materials also showed some differences caused by the doping sites. The intensities of the Eu3+ PL peaks derived from the 5D0-7F1 transitions and those from the 5D0-7F2 transitions were markedly different between Eu3+ at A sites and those at B sites because of the different site symmetries. The splitting of the intense Tb3+ PL peaks originating from the 5D4-7F5 transitions and the absence of PL peaks from 5D3-7FJ transitions were found only for Tb3+ at B sites because of the strong crystal field at B sites. In addition to the PL spectra, the positions of PLE peaks originating from charge transfer transitions in Eu3+ and the 4f-5d transitions in Tb3+ depended on the doping sites. The successful site-selective doping enabled us to clarify the site-sensitive luminescence properties of Eu3+ and Tb3+ doped in the perovskite-type LaLuO3.