LAUSR

Abstract An electroluminescent device composed of In2O3:Sn electrode, Ca0.6Sr0.4TiO3:Pr red phosphor with the emission peak at 613 nm, and SnO2:Sb electrode thin films is prepared using a sol-gel and firing method. The electrical and electroluminescence properties are investigated by monitoring the current and luminance. Pulse-like electroluminescence is observed immediately after SnO2:Sb is polarized either negatively or positively. Direct current (DC) electroluminescence is observed only when SnO2:Sb is negatively polarized. During the DC electroluminescence, anomalous relaxation phenomena are observed: the current decreases but the luminance increases with increasing time at a constant voltage. These results are discussed based on Waser's model, which suggests that Ca0.6Sr0.4TiO3:Pr separates into n-type and p-type semiconducting regions due to electromigration of the oxygen vacancies.