Credit: MI Zhaohong
Figure (A) shows the schematic of proton-beam-induced luminescence (ionoluminescence) in a transmission thin scintillator comprising CsPbBr3 nanocrystals (cubic structure), and proton-induced ionisation to produce secondary electrons (δ-rays). Figure (B) presents the proposed mechanism of proton scintillation, including high-density exciton formation via proton-induced upconversion pumped by low-energy δ-rays and impact ionisation pumped by high-energy δ-rays (left panel), biexciton formation via exciton-exciton interaction (middle panel), and de-excitation processes via radiative recombination of biexcitons accompanied by a fast non-radiative Auger process (right panel).