Optical Band Gap and Photoluminescence Studies of Samarium-Doped Barium Zirconate Perovskite Prepared by Solid State Reaction Route

Abstract

The structural and optical properties of Ba1–xSm2x/3ZrO3 (x = 0.02, 0.04, 0.06, 0.08, 0.10) ceramics prepared by the solid-state reaction method are considered. The x-ray diffraction data confirm the cubic perovskite phase of all the compositions with space group Pm $$ \overline{3}\hbox{--} \mathrm{m} $$ . The effect of Sm3+ substitution on the optical band gap and photoluminescence properties of barium zirconate are discussed. The optical band gap decreases from 3.43 to 2.98 eV with increasing Sm3+ content. The Urbach energy has been found to increase with rise in concentration of dopant species. The photoluminescence spectra show an intense violet–blue emission characteristic of the barium zirconate perovskite. Visible emission due to intra-4f transitions of Sm3+ ions from 4G5/2 higher excited state to 6Hj ( j = 5/2, 7/2, 9/2 etc.) ground states has been observed in the range of 550–700 nm.