Effect of ion occupancy and Li+ ion doping on luminescence characteristics of CaLaGaO4:Bi3+ blue phosphor

In recent years, the application of Bi3+ ions doped luminescent materials in the field of optoelectronics has attracted wide attention. In this paper, CaLaGaO4:xBi3+(x = 0.005, 0.0075, 0.01, 0.0125, 0.015, 0.02, 0.025mol) blue phosphors were synthesized by high temperature solid phase method. The theoretical and experimental bandgap values after Bi3+ ions doping is reduced, indicate that electrons can be transferred from valence band to conduction band better after Bi3+ ions doping, which increases the carrier concentration and improves the luminous efficiency. In addition, due to the doping of Li+ ions under 365nm excitation, the emission intensity is increased by 2.5 times, shows high brightness blue light, with excellent thermal stability (423K/303K = 83%), quantum efficiency is 56%, and CaLaGaO4:0.01Bi3+, 0.008Li+ phosphor was mixed with (Ba,Sr)2SiO4:Eu2+ commercial green phosphor and (Ca,Sr)AlSiN3:Eu2+ red phosphor in a certain proportion. The WLED combined with 365nm chip has a high color rendering index Ra = 90.2. Relevant color temperature CCT = 5502K.