Crystallization and nucleation of the perovskite layer in the mesoscopic perovskite solar cells (PSCs) depend on the nucleation sites of the electron transport layer (ETL). The porosity optimization of TiO₂ film as an efficient ETL plays an important role in the performance improvement of PSCs. In the present study, nontoxic carbon spheres synthesized with uniform morphology and controllable size under hydrothermal conditions and used as a template to generate the tunable porous TiO₂ films. Furthermore, the effect of porosity modification of TiO₂ on the formation of perovskite films with large grain size is studied in an ambient atmosphere with humidity higher than 50%. The best TiO₂ film is produced with carbon spheres 8 wt% (C8), which results in the formation of a pinhole‐free, and compact‐packed perovskite layer. The fully air processed PSC device with the ETL made of C8 film exhibits an efficiency of 16.66% with reduced hysteresis, which is much superior in performance compared to the standard cell (11.72%). It is believed that this porosity optimization of TiO₂ layer is a simple practical strategy for improved stability of fully air processed efficient perovskite solar cells and usable for the fabrication of reproducible compact perovskite layers in uncontrolled laboratories.

中文翻译：

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使用可调节孔结构的TiO2糊剂，完全环境空气处理的钙钛矿太阳能电池的效率和稳定性增强

介观钙钛矿太阳能电池（PSC）中钙钛矿层的结晶和成核取决于电子传输层（ETL）的成核位置。TiO ₂薄膜作为一种有效的ETL的孔隙率优化在PSC的性能改善中起着重要的作用。在本研究中，无毒碳球在水热条件下以均匀的形态和可控制的大小合成，并用作生成可调谐多孔TiO ₂膜的模板。此外，在湿度大于50％的环境气氛中研究了TiO ₂的孔隙率改性对形成大晶粒钙钛矿膜的影响。最好的TiO ₂薄膜是用8 wt％（C8）的碳球生产的，从而形成了无针孔且紧密堆积的钙钛矿层。具有由C8膜制成的ETL的完全空气处理的PSC器件具有16.66％的效率，并具有降低的磁滞，与标准电池（11.72％）相比，其性能要优越得多。可以相信，TiO ₂层的孔隙率优化是一种简单的实用策略，可提高经充分空气处理的高效钙钛矿太阳能电池的稳定性，并可用于在不受控制的实验室中生产可复制的紧凑型钙钛矿层。