Enhanced Seebeck Effect of a MAPbBr3 Single Crystal by an Organic and a Metal Modified Layer

Abstract The organic–inorganic hybrid lead halide perovskite single crystal has drawn much attention of researchers for excellent characteristics, such as more excellent stability than the polycrystalline film. However, during the crystal preparation process, there are inevitably generated surface defect states, which seriously affect the charge transport properties of the single crystal. In this article, the MAPbBr3 single crystal is prepared by the inverse temperature crystallization method, the semiconductor characteristics of the crystal surface defect states are studied by the Seebeck effect method, and the crystal Seebeck coefficient is enhanced. It is confirmed that there are N‐type defect states on the surface of the MAPbBr3 single crystal. Then the organic semiconductor layer and metal surface modified layer are utilized to reduce the concentration of defects and got the enhancement of the Seebeck coefficient of MAPbBr3 single crystal. At last, the Au/MAPbBr3/PFO/Au structure device is designed and prepared to improve the thermoelectric properties of the MAPbBr3 single crystal. Results show that the thermal voltage keeps increasing, and the Seebeck coefficient is also enhanced.