Shine red and yellow photoluminescence in GdAlO3-δ powders

GdAlO3-delta (delta = 0.0, 0.1 and 0.2) compounds were prepared by the conventional solid-state method. XRD patterns revealed that all samples present a major orthorhombic structure. An intense red and a yellow photoluminescence (PL) emissions were observed at room temperature for delta = 0.0 and delta not equal 0.0 samples, respectively. The red emission was related to the singly ionized oxygen vacancies V-O. The production of doubly ionized oxygen vacancies V-O lead to the appearance of a yellow color observed directly from delta = 0.1 and 0.2 samples. The presence of singly and doubly ionized clusters was found to play an important role in the formation of hole-electron pairs and to give rise to the PL emission. The presence of singly ionized oxygen vacancies was confirmed by the EPR study. (C) 2015 Elsevier B.V. All rights reserved.