Fabrication of CsPbBr3 films with high quality using a simple method

Inorganic perovskite CsPbBr3 is a material used for fabricating highly efficient and stable perovskite solar cells. In this work, a two-step infiltration-spinning method is proposed to obtain CsPbBr3 films with pure phase. Phase transformations between CsPb2Br5, CsPbBr3 and Cs4PbBr6 are investigated by controlling the contact time between the CsBr solution and the PbBr2 substrate. CsPbBr3 films with large grain sizes are obtained after high temperature post-treatment. The CsPbBr3-based solar cells show a high efficiency (approximately 7%) with a short-circuit current density of 6.68 mA cm(-2), an open-circuit voltage of 1.47 V and a fill factor of 70.9% under standard solar illumination.