TiO₂ is one of the most efficient and widely used materials for electron‐transporting layer (ETLs) in perovskite solar cells (PSCs). The formation of efficient TiO₂ layers is generally carried out at high temperature by baking at a temperature >400 °C or by vacuum deposition (e.g., atomic layer deposition and E‐beam). In this study, the preparation of a TiO₂ ETL for PSCs is reported with excellent properties at low temperatures based on the synthesis of a stable TiO₂ colloidal aqueous solution and spray coating. The prepared TiO₂ colloids are able to produce a dense and uniform ETL even if it is simply dried at 100 °C after spray coating. It is believed that this is owing to the peroxo functional group remaining on the surface of the TiO₂ colloids. The TiO₂ ETLs, combined with the TiO₂ underlayer formed by chemical bath deposition, and the sprayed TiO₂ colloids allowed the fabrication of PSCs with performance similar to those of PSCs produced by annealing at 450 °C with a TiO₂ paste. The PSCs fabricated entirely at 100 °C demonstrated power conversion efficiency of 22.7% in small cells, and 19.0% in mini‐modules.

中文翻译：

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用于高效钙钛矿太阳能电池的TiO2胶体喷涂电子传输层

TiO ₂是钙钛矿太阳能电池（PSC）中电子传输层（ETL）的最有效和最广泛使用的材料之一。有效的TiO ₂层的形成通常是在高温下通过在> 400°C的温度下烘烤或通过真空沉积（例如原子层沉积和电子束）进行的。在这项研究中，据报道，基于稳定的TiO ₂胶体水溶液的合成和喷涂，用于PSC的TiO ₂ ETL的制备具有优异的低温性能。制备的TiO ₂胶体即使喷涂后在100°C下简单干燥，也能产生致密且均匀的ETL。认为这是由于过氧化物官能团残留在TiO ₂胶体的表面上。TiO ₂ ETL与通过化学浴沉积形成的TiO ₂底层以及喷涂的TiO ₂胶体相结合，可以制造性能与在450℃下用TiO ₂糊剂退火的PSC相似的PSC 。完全在100°C下制造的PSC在小型电池中的功率转换效率为22.7％，在小型模块中为19.0％。