In this work, we present a detailed optical investigation of the effects of the environment on the photoluminescence (PL) spectra and the relaxation dynamics of pristine and aged CsPbBr3 nanocrystal (NC) thin films. We demonstrate that, contrary to previous results on similar NCs, the PL intensity of pristine NCs is higher when the sample is in wet air than in vacuum, due to the passivation of defects reducing the free exciton trapping and the bound excitons non-radiative relaxation. The aged NCs show a PL intensity increase in wet air nine times stronger than the pristine ones, due to an interplay between static and dynamic effects, increasing the number of emitting NCs and reducing the non-radiative recombination rate of free excitons. These results improve the understanding of the possible interactions between perovskite NCs and the environment, which could be relevant for the development of optical gas sensors exploiting perovskite NCs.
|Original language||English (US)|
|Journal||Applied Sciences (Switzerland)|
|State||Published - Mar 23 2020|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: Omar F. Mohammed from KAUST Solar Center (Kingdom of Saudi Arabia) is acknowledged for the possibility to exploit his know-how on the nanocrystals synthesis, necessary for the realization of the samples used in this experiment.