Bi3+/Sm3+ co-doped LiTaO3 photochromic perovskites: an ultrafast erasable optical information storage medium

Abstract

Inorganic photochromic materials hold great scientific and technological promise in the field of optical information storage due to their numerous advantages, including an extended color change duration, exceptional fatigue resistance, and robust thermal stability. However, their practical application has been hindered by relatively slow coloring and bleaching rates. In this study, we present a P-type photochromic perovskite material, LiTaO₃:Bi³⁺/Sm³⁺, with an ultra-fast optical response. LiTaO₃:Bi³⁺/Sm³⁺ exhibits a rapid coloring time of approximately 25 seconds and an ultra-fast bleaching time of approximately 1 second, achieved through alternating 254 nm and 365 nm light irradiation. Notably, the photobleaching rate of LiTaO₃:Bi³⁺/Sm³⁺ is currently the fastest among all reported inorganic photochromic materials. The prepared LiTaO₃:Bi³⁺/Sm³⁺ material exhibits a maximum color change contrast of 26.49% and excellent fatigue resistance. The codopant Bi³⁺ plays a critical role in creating traps within the host lattice, which greatly enhances photochromism contrast and enables efficient long afterglow luminescence. These dual properties make the material suitable for dual-mode optical information storage in both bright and dark fields. Finally, the excellent optical properties of LiTaO₃:Bi³⁺/Sm³⁺ are demonstrated in its application for erasable optical information storage vividly.