Increasing photoluminescence yield of CsPbCl3 nanocrystals by heterovalent doping with Pr3+

CsPbCl3 perovskite nanocrystals are doped with heterovalent Pr3+ using hot-injection method. These Pr3+- doped CsPbCl(3 )nanocrystals exhibit a dramatically improved absolute photoluminescence quantum yield (PLQY) compared to the undoped CsPbCl3, reaching 78.9 % PLQY at 9 % Pr-substitution. The crystal structure modification upon Pr3+ doping and luminescence mechanism are investigated using conventional optical spectroscopy and synchrotron X-ray spectroscopy (i.e., X-ray absorption fine structure and X-ray excited optical luminescence). Both the Pr3+ and Cl- are found contributing to the luminescence enhancement, and their individual roles in luminescence enhancement are analyzed.