Xiao Liu

Highly crystalline SnO2 is demonstrated to serve as a stable and robust electron-transporting layer for high-performance perovskite solar cells. Benefiting from its high crystallinity, the relatively thick SnO2 electron-transporting layer (≈120 nm) provides a respectable electron-transporting property to yield a promising power conversion efficiency (PCE)(18.8%) Over 90% of the initial PCE can be retained after 30 d storage in ambient with ≈70% relative humidity. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Perovskite solar cells (PSCs) emerging as a promising photovoltaic technology with high efficiency and low manufacturing cost have attracted the attention from all over the world. Both the efficiency and stability of PSCs have increased steadily in recent years, and the research on reducing lead leakage and developing eco-friendly lead-free perovskites pushes forward the commercialization of PSCs step by step. This review summarizes the main progress of PSCs in 2020 and 2021 from the aspects of efficiency, stability, perovskite-based tandem devices, and lead-free PSCs. Moreover, a brief discussion on the development of PSC modules and its challenges toward practical application is provided.

Abstract Tin‐based perovskites with narrow bandgaps and high charge‐carrier mobilities are promising candidates for the preparation of efficient lead‐free perovskite solar cells (PSCs). However, the crystalline rate of tin‐based perovskites is much faster, leading to abundant trap states and much lower open‐circuit voltage ( V oc ). Here, hydrogen bonding is introduced to retard the crystalline rate of the FASnI 3 perovskite. By adding poly(vinyl alcohol) (PVA), the OH…I − hydrogen bonding interactions between PVA and FASnI 3 have the effects of introducing nucleation sites, slowing down the crystal growth, directing the crystal orientation, reducing the trap states, and suppressing the migration of the iodide ions. In the presence of the PVA additive, the FASnI 3 –PVA PSCs attain higher power conversion efficiency of 8.9% under a reverse scan with significantly improved V oc from 0.55 to 0.63 V, which is one of the highest V oc values for FASnI 3 ‐based PSCs. More importantly, the FASnI 3 –PVA PSCs exhibit striking long‐term stability, with no decay in efficiency after 400 h of operation at the maximum power point. This approach, which makes use of the OH…I − hydrogen bonding interactions between PVA and FASnI 3 , is generally applicable for improving the efficiency and stability of the FASnI 3 ‐based PSCs.