Modulation of anisotropic photoluminescence and photocurrent in PEA2PbI4 single-crystal thin films

The fundamental understanding of exciton physics and the anisotropic behavior of excitons and charge carriers in perovskite materials are pivotal to controlling the orientation of emission dipoles and the polarization of photocurrents to enhance the efficiency of light-emitting diodes (LEDs) and polarization photodetectors.However, it is not easy to clarify these fundamental physics and optoelectronic properties in traditional inorganic 3D perovskite polycrystalline thin films.Here, we found three narrow emission peaks with one broad peak from neutral excitons at 78 K in hybrid perovskite PEA 2 PbI 4 single crystals.The out-of-plane electric field can induce the dissociation of the excitons with a larger decrease in the emission intensity of the exciton with a higher out-of-plane component.Moreover, the photocurrent can be greatly increased up to a maximum of 11 times with the tuning of excitation polarization from 90to 0.These results deepen our understanding of the anisotropic exciton and charge carrier physics of perovskite materials to promote the development of highly efficient LEDs and polarization photodetectors.