Controlled Synthesis and Doping of MAPbBr₃ Single Crystals for Enhanced Scintillation Performance at Cryogenic Temperatures

High Resolution Image Download MS PowerPoint Slide To date, hybrid organic–inorganic halide perovskites still attract significant attention due to their intrinsic versatility in optoelectronic devices and scintillation applications. This study aims to investigate the effect of Rb and Li doping on the structural, optical, and luminescence properties of methylammonium lead bromide (MAPbBr 3 ) single crystals (SCs), with particular emphasis on enhancing their cryogenic scintillation performance. Raman, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses confirmed minimal structural changes upon doping. Photoluminescence (PL) spectra showed that Li-doped 0.4M-tetrahydrofuran (THF) SC exhibits intense surface emission intensity and a long decay time (100 ns) compared to that of Li-doped control 1M-THF SC, while Rb-doped 0.4M-THF SC has a short decay time compared to that of Rb-doped control 1M-THF SC (17.5 ns). Radioluminescence (RL) analysis displayed strong excitonic luminescence, reduced thermal quenching, and improved thermal stability with dopant incorporation in the orthorhombic phase below 50 K. Furthermore, for both dopants 0.4M-THF SCs exhibit a remarkable RL light yield, surpassing the control crystal of 1M-SCs by more than 2-fold. 0.4M-THF samples consistently outperformed control 1M-THF samples in thermal stability and emission efficiency, with Li-doped SCs showing slightly better scintillation performance than Rb-doped ones, making them highly suitable for cryogenic scintillation applications.