Studying of the pressure-induced photoluminescence characteristics of CsPbI3 nanocrystals

The carrier dynamics and the radiative channel together govern the performance of optoelectronic devices based on perovskite nanocrystals (NCs). In order to further understand their relationship, the pressure-dependent spectral test is employed, which scans the photo-physical properties of CsPbI 3 NCs. The carrier dynamics involving monomolecular and bimolecular recombination slow down with pressure, which decreases the photoluminescence quantum yield (PLQY). The former is affected by the variance of the shallow defect and both of them are sensitive to the phase transition at 0.39 GPa, which is confirmed by the pressure-dependent PL and absorption spectral data. The radiative lifetime , originated from a part of bimolecular recombination, prolongs with pressure, even though the PLQY decreases simultaneously. The photo-physical characteristics as mentioned is mainly originated from the lattice shrinkage induced by pressure. Our work provides clues for optimizing the performance of lighting and displaying devices based on inorganic perovskites NCs.