Design of a defect‐induced orange persistent luminescence phosphor BaZnGeO <sub>4</sub> :Bi <sup>3+</sup>
Wenzhi Sun, Mengmeng Jiao, Liyan Fan, Ruijuan Zhang, Xinxin Zhang, Hongwu Zhang
Abstract
Abstract We report a novel bright orange persistent luminescence (PersL) phosphor BaZnGeO 4 :Bi 3+ with broad emission and PersL spectra. Its crystal structure, photoluminescence (PL) spectra, thermoluminescence (TL) spectra and PersL spectra were investigated in detail. The two emission bands at 440 nm and 595 nm originate from Bi 3+ ions in normal Ba 2+ sites (Bi1) and Ba 2+ sites close to vacancy defects (Bi2), respectively. The introduction of and defects improves the emission intensity of Bi2 more than that of Bi1, demonstrating that Bi2 is related to the vacancy defects. The orange emission and PersL properties of BZGO:Bi 3+ can be improved when a little and defects are introduced, because the introduction of and defects makes it easier for Bi 3+ to enter in Ba 2+ sites; and for PersL, and defects can perform as the effective trap centers to capture more charges, which is beneficial for PersL. BZGO:Bi 3+ has quite good thermal stability, and the bright orange PersL can be observed by the naked eye for 1 h. Finally, a feasible PersL mechanism of BZGO:Bi 3+ was proposed to clarify the PersL‐generation process.