Suppressing Phase Segregation in CsPbIBr2 Films via Anchoring Halide Ions toward Underwater Solar Cells

Inorganic CsPbIBr2 perovskite solar cells (PSCs) have accomplished many milestones, yet their progress has been constrained by ion migration and phase separation. This study explores the modulation of perovskite crystallization kinetics and halide ion migration through chlorobenzene (CB) antisolvent with bis(pentafluorophenyl)zinc (Zn(C6F5)2) additive. The photoluminescence and absorption spectra reveal the significantly reduced phase segregaton in CsPbIBr2 film treated by CB with Zn(C6F5)2. Moreover, this research analyzes the CsPbIBr2 film's free carrier lifetime, diffusion length, and mobility using time-resolved microwave conductivity and transient absorption spectroscopy after Zn(C6F5)2 modification. Consequently, the modified CsPbIBr2 PSCs offer a 12.57% power conversion efficiency (PCE), the highest value among CsPbIBr2 PSCs with negligible hysteresis and prolonged stability. Furthermore, under 1-m-deep water, CsPbIBr2 PSCs display a PCE of 14.18%. These findings provide an understanding of the development of phase-segregation-free CsPbIBr2 films and showcase the prospective applications of CsPbIBr2 PSCs in underwater power systems.

Automated summary

This study investigates the control of crystallization kinetics and halide ion migration in CsPbIBr2 perovskite solar cells through the modulation of chlorobenzene antisolvent and bis(pentafluorophenyl)zinc additive. The addition of Zn(C6F5)2 significantly reduces phase segregation in CsPbIBr2 films, as observed from photoluminescence and absorption spectra. Furthermore, the modified CsPbIBr2 PSCs exhibit a power conversion efficiency of 12.57% with negligible hysteresis and increased stability. Under 1-m-deep water, the PCE of CsPbIBr2 PSCs reaches 14.18%. These findings provide insights into the development of phase-segregation-free CsPbIBr2 films and demonstrate the potential applications of CsPbIBr2 PSCs in underwater power systems.