Bi-induced photochromism and photo-stimulated luminescence with fast photochromic response for multi-mode dynamic anti-counterfeiting and optical information storage

Abstract

Materials with photochromic (PC) and photo-stimulated luminescence (PSL) properties have been increasingly recognized as promising candidates in information storage and anti-counterfeiting applications. However, the general reported doping method cannot realize both PC and PSL properties in one inorganic material due to the unmanageable intrinsic electronic structure, which limits its applications in multi-mode information storage. Herein, we report a single phosphor with PC, PSL, thermal luminescence (TL), and afterglow properties to substitute the common composites utilized in multi-mode systems through the systematic defect management strategies. By doping Bi into LiNbO3 (LNO):Pr3+ phosphor, it shows a fast response time (∼1 s) and a large reflectivity difference of 34 % between the bleached and colored states under 365 nm excitation. In addition, it also presents a wavelength-dependent bleaching character. The first-principle calculations reveal that such properties result from the presence of trap states in the band gap of LNO:Pr3+ phosphor through Bi-doping, which enable us to design the device with multiple dimensions of anti-counterfeiting and optical information storage performances. This finding stimulates the exploration for designing multi-mode responsive luminophores for future generation of information storage.