K+ doping effect on grain boundary passivation and photoelectronics properties of NiOx/perovskite films

• Published in: Chemical physics letters Vol. 757; p. 137882
• Main Authors: Zhou, Zixiao, Zou, Xiaoping, Zhu, Jialin, Cheng, Jin, Ren, Haiyan, Chang, Chuangchuang, Yao, Yujun, Chen, Dan, Yu, Xing, Li, Guangdong, Wang, Junqi, Liu, Baoyu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 16.10.2020
• Subjects: K+ doping; Passivation; Phase transition; Photoelectronics properties; Two-step method; Two-step method; K+ doping; Photoelectronics properties; Passivation; Phase transition
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2020.137882

[Display omitted] •Trace K doping resulted in larger size and boundary passivation of perovskite grains.•Phase transition of MAPbI3 was observed under high doping degree in XRD pattern.•Red shift of MAPbI3 was observed under high doping degree in absorption spectra.•Major charge carrier type of perovskite could be modulated with K+ doping. 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 performance of PSCs. In this paper, the K+ was introduced into the CH3NH3PbI3 (MAPbI3) 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 MAPbI3 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 observed when K+ was introduced, which laid a basis for future investigation on inverted homo-junction solar cells.