Origins and Suppression of Sn(II)/Sn(IV) Oxidation in Tin Halide Perovskite Solar Cells

Abstract

Tin halide perovskite solar cells (TPSCs) have attracted aggressive research interest in the emerging perovskite photovoltaic devices due to their eco-friendliness as compared to their lead halide counterparts. However, the easy Sn(II)/Sn(IV) oxidation of tin perovskites is a serious impediment to the development of TPSCs. Therefore, a clear understanding of the mechanisms, origins, and effects of the oxidation is essential to further boost the performance and stability of TPSCs. Herein, a systematic overview of the physicochemical process for the Sn(II)/Sn(IV) oxidation in TPSCs from the starting precursors to the final devices is presented. In addition, the effects of oxidation on the performance of TPSCs are then reviewed from crystal structure, defect chemistry, and optoelectronic properties. More importantly, the key issues to suppress the Sn(II)/Sn(IV) oxidation are seriously discussed on the basis of the reported antioxidation strategies. Finally, the challenges and outlooks toward TPSCs with higher power conversion efficiency and stability are proposed.

Stable Inorganic Colloidal Tin and Tin–Lead Perovskite Nanocrystals with Ultralong Carrier Lifetime via Sn(IV) Control

“…To substantiate this reduction reaction, we prepared (SnI 4 + SnO 2 )TOP by dissolving the oxidation products of solid SnI 2 (i.e., SnI 4 and SnO 2 , as seen in Figure S13) into TOP within a glovebox. Figure d intuitively viewed the sum of the kinetic energy of a core–core–core (Sn M 4 N 4,5 N 4,5 ) Auger line, E ink , and the binding energy, E b , of a core electron (Sn 3d 5/2 ), Auger parameters, α′, in a Wagner format , to analyze valence and coordination information. Notably, both (SnI 4 + SnO 2 )TOP and SnI 2 (TOPO) exhibit the same valence and coordination condition of Sn ions, as evidenced in Figure d (with the data for E ink and E b sourced from Figure S14).…”

Growth methods' effect on the physical characteristics of CsPbBr3 single crystal

“…[1][2][3][4][5] The field of perovskite materials, particularly in photovoltaics, has been extensively studied, with various approaches suggested for improving device efficiency, including enhancements in crystallinity, meticulous interface optimization, and the incorporation of additives. [6][7][8] Perovskite devices exhibit diverse configurations, such as polycrystalline films, single crystals (SCs), nanocrystals, and quantum dots, highlighting the remarkable processability of perovskite materials, supported by their inherent defect tolerance. [9][10][11] Among these configurations, SCs offer advantages over polycrystalline thin films, including higher carrier mobilities and increased environmental resilience.…”

Regulating the Crystallization and Carrier Dynamics for High-Performance Quasi-2D Tin Perovskite Solar Cells

“…Lead-free tin perovskite solar cells (TPSCs) have attracted much attention, due to their excellent photoelectric properties, such as close-to-ideal band gap, high carrier mobility, and low toxicity. − Currently, the power conversion efficiency (PCE) of TPSCs has exceeded 14%. , However, due to its inherent characteristics, Sn 2+ is prone to oxidation, resulting in high level of p - doping and serious carrier recombination. − Besides, the tin perovskites have a high Lewis acidity, which will lead to rapid crystallization and difficulty in depositing high-quality films. − …”