Resonantly enhanced multiple exciton generation through below-band-gap multi-photon absorption in perovskite nanocrystals.

ABSTRACT: Multi-photon absorption and multiple exciton generation represent two separate strategies for enhancing the conversion efficiency of light into usable electric power. Targeting below-band-gap and above-band-gap energies, respectively, to date these processes have only been demonstrated independently. Here we report the combined interaction of both nonlinear processes in CsPbBr3 perovskite nanocrystals. We demonstrate nonlinear absorption over a wide range of below-band-gap excitation energies (0.5-0.8 Eg). Interestingly, we discover high-order absorption processes, deviating from the typical two-photon absorption, at specific energetic positions. These energies are associated with a strong enhancement of the photoluminescence intensity by up to 105. The analysis of the corresponding energy

SUBMITTER: Manzi A 

PROVIDER: S-EPMC5904181 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature