Improving persistent luminescence in pressure-tuned CsPbBr nanocrystals by Ce doping.

The pressure-dependent photoluminescence kinetics of CsPbBr:Ce quantum dots was investigated by steady-state and time-resolved photoluminescence spectroscopy. Here, we propose a novel strategy to improve the persistent luminescence of CsPbBr quantum dots under high pressure through doping of Ce ions. Under high pressure, the peak intensity and energy of CsPbBr:Ce quantum dots decreased more slowly than those of CsPbBr quantum dots, which is manifested by pressure coefficient reductions of 0.08 a.u. GPa and 0.012 eV GPa, respectively. The time-resolved photoluminescence measurements revealed that Ce-doping can significantly modulate the photoluminescence kinetics to shorten the lifetimes of CsPbBr quantum dots with increasing pressure. These phenomena were absolutely different from those observed in CsPbBr quantum dots. These findings will be useful for broadening the application of optical devices based on all-inorganic perovskite materials under high pressure.