A new strategy for monitoring the charge transfer from perovskite thin films to electron transport layers using a heterodyne transient grating technique

Phys Chem Chem Phys. 2023 May 31;25(21):14742-14748. doi: 10.1039/d3cp01496g.

Abstract

We fabricated CH3NH3PbI3 (MAPbI3) thin films with and without a ZnO layer and measured the heterodyne transient grating (HD-TG) responses of each film to investigate the charge injection dynamics from MAPbI3 to ZnO, based on the component arising from the recombination of the surface trapped electrons in the ZnO layer with the remaining holes in MAPbI3. In addition, we observed the HD-TG response of the MAPbI3 thin film coated with the ZnO layer in which phenethyl ammonium iodide (PEAI) was inserted between two layers as a passivation layer and confirmed that the charge transfer was enhanced when PEAI existed, based on the increase in the amplitude of the component arising from the recombination and its acceleration.