The electron transport layer (ETL) plays a crucial role for efficiency and stability of perovskite solar cells (PSCs). As a promising low-temperature ETL, tin oxide still requires complicated surface chemical decoration or heat-treatments to further passivate the defects and adjust band energy level to improve the optoelectronic performance of the device. Herein, a novel and efficient strategy is developed for the solution prepared annealing-free SnO₂ ETL for PSCs. Through simple electrochemical regulation, the elemental composition, valence ratio of Sn, concentration of oxygen vacancies, hydroxyl groups, and dopant ions are precisely modified with the optimized the energy band, reduce the defect density, and enhance high carrier transport for PSCs. Thus, an increase of power conversion efficiency (PCE) from 21.6% to 24.7% and a high V_OC of 1.19 V is obtained. The modified devices maintain 95% of the initial PCE after 2000 h of storage, and 80% of the initial PCE after 900 h of aging in an atmospheric environment at 75 °C and RH 20 ± 5%. Moreover, the perovskite solar module based on the as made SnO₂ achieve a high PCE of 21.3%.

中文翻译：

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用于高性能钙钛矿太阳能电池的免退火 SnO2 的电化学还原和离子注入

电子传输层（ETL）对于钙钛矿太阳能电池（PSC）的效率和稳定性起着至关重要的作用。作为一种有前景的低温ETL，氧化锡仍然需要复杂的表面化学修饰或热处理来进一步钝化缺陷并调整能带能级以提高器件的光电性能。本文开发了一种新颖有效的策略来制备溶液制备的免退火 SnO ₂PSC 的 ETL。通过简单的电化学调节，通过优化能带对元素组成、Sn价态、氧空位浓度、羟基和掺杂离子进行精确修饰，降低缺陷密度，增强PSC的高载流子传输。_{因此，功率转换效率（ PCE}）从21.6％增加到24.7％，并且获得了1.19V的高VOC 。修改后的器件在储存2000小时后仍保持初始PCE的95%，在75℃和RH 20±5%的大气环境中老化900小时后仍保持初始PCE的80%。此外，基于所制备的SnO _{2 的}钙钛矿太阳能电池组件实现了21.3%的高PCE。