Influence of N-type electron acceptors in perovskite absorbers for stabilized perovskite absorbers for high-performance perovskite solar cells

Abstract

In this study, the impact of n-type organic electron acceptors incorporated in perovskite absorbers via antisolvent-assisted crystallization process is investigated on optical, electrical, and photovoltaic properties of perovskite solar cells (PSCs). The study examines the effect of three representative electron acceptors, including fullerene derivative (PC61BM), non-fullerene acceptor (ITIC), and fluorinated non-fullerene acceptor (ITIC-4F). The findings demonstrate that the inclusion of these electron acceptors stabilizes perovskite absorbers due to strong interaction between the organic acceptors and [PbI6]4- octahedra, leading to the successful passivation of defective antisites. Furthermore, ITIC-4F plays a crucial role in the tailored electronic structure of the perovskite absorber surface, facilitating efficient charge transport and suppressing carrier recombination in the device. The synergetic effect of defect passivation and electrical doping achieved by ITIC-4F resulted in an efficiency improvement of 17.31 % of MAPbI3-based PSCs under 1-Sun illumination, exceeding that of the pristine device (15.62 %) under the same conditions. The device passivated with ITIC-4F also delivered an efficiency of 20.00 % under dim-light irradiation conditions for indoor photovoltaic applications. The results highlight the potential of n-type organic semiconducting molecules as effective additives in the antisolvent-assisted crystallization of perovskite absorbers, offering valuable insights into the design of organic semiconducting additives for improving the film quality of perovskite absorbers and achieving high-performance PSCs. The findings provide a foundation for future research aimed at enhancing the optoelectronic properties and photovoltaic performance of PSCs.