The properties of perovskite solar cells with novel MAPbBr3/CsPbBr3 double absorber

Abstract

Abstract Perovskite solar cells (PSCs) based on CsPbBr3 have garnered considerable attention due to their high stability and all-inorganic components. Although thermal annealing is a conventional and effective method to improve the quality of CsPbBr3 films, property improvement strategies are still scarce, especially for the vapor deposition process. In this work, a MAPbBr3 layer is introduced at the TiO2 and CsPbBr3 interface to construct a double-absorber heterojunction structure. It is found that the cubic phase of CsPbBr3 is formed directly on the MAPbBr3 underlayer due to the epitaxial growth. Furthermore, the heterojunction formed at the MAPbBr3/CsPbBr3 interface contributes to the superior extraction of the light-generated carriers. A power conversion efficiency (PCE) of 6.53% is obtained for the PSC with a double-absorber design. Despite the thickness of the epitaxial layer being shrunken after annealing at 150 °C for 30 min, a PCE of 5.90% is achieved, indicating the high thermal stability of the double-absorber device. Our work provides a new insight into quality engineering for the perovskite deposited by the vapor deposition process.