Intense piezoluminescence in LiTaO3 phosphors doped with Pr3+ ions

A novel piezoluminescent (PZL) phosphor was prepared by doping Pr3+ ions into ferroelectric LiTaO3 matrices, and their crystal structure and multi-luminescent performance were investigated. A slightly Li-rich nonstoichiometric design gave the phosphors optimized PZL behavior with favorable recoverability. Excited by 240 nm radiation, two strong photoluminescent (PL) emission bands lay around 511 and 615 nm, which corresponded to Pr3+ transitions of 3P0 to 3H4 and 1D2 to 3H4, respectively. Nevertheless, the 3P0 to 3H4 transition was detectably suppressed in AG/PZL spectra with 1D2 to 3H4 becoming dominant, which was possibly owing to the effect of trap level distribution on direct tunneling possibilities. In this context, a probable mechanism was proposed to explain the multi-luminescent process in LiTaO3:Pr3+. This study was aimed at exploring novel PZL materials for fundamental research and applications in multifunctional devices.