K+ Doping Effect On Grain Boundary Passivation And Photoelectronics Properties Of Niox/Perovskite Films

As a new type of solar cells, perovskite solar cells (PSCs) have received widespread attention. The grain growth and surface morphology of perovskite thin films are considered to have an important influence on the perfor-mance of PSCs. In this paper, the K+ was introduced into the CH3NH3PbI3 (MAPbI(3)) and the effect of different doping concentration on the morphology, photophysical properties, and semiconductor characteristics of the perovskite films was investigated. From experiments, we found that the incorporation of low-concentration K+ has a passivation effect on the grain boundaries, which reduces the defect density at interface. The phase transition and obvious red shift of MAPbI(3) could be seen under high doping concentration in XRD pattern and absorption spectrum, respectively. The modulation of the perovskite layer major charge carrier type was ob-served when K+ was introduced, which laid a basis for future investigation on inverted homo-junction solar cells.