The dense, uniform and conformal electron transport layers (ETLs) will largely promote charge separation and extraction. Here, the mixed acid (hydrochloric acid and nitric acid) was used to regulate preparation process and enhance utilization of materials, and the colloids of tin oxide (SnO2) nanocrystals were prepared through hydrothermal process. The complete dissolution of Sn source can increase purity, produce homogeneous precursor, reduce grain sizes and improve film-coverage. As confirmed, a coherent interlayer at the SnO2 ETLs/perovskite interfaces will be achieved by coupling a Cl-bonded SnO2 film with a Cl-containing perovskite precursor. This thin coherent interlayer will largely reduce interface traps, enhance rapid carrier extraction, and impede charge recombination. The uniform polymer phase of (PEO)120-(PPO)30 will be used to passivate traps at the grain boundaries of perovskite films and further improve the photovoltaic performance. The maximum energy conversion efficiency (23.17%, a VOC of 1.153 V, a JSC of 24.75 mA cm−2 and a FF of 0.812) of perovskite solar cells was achieved. The charge separation, extraction, and recombination kinetics (charge dynamic process) was determined by the related characterization techniques. The functionalized SnO2-ETLs and formed coherent interlayer will provide a simple strategy to effectively decrease interface traps, enhance charge extraction, and facilitate development of perovskite solar cells.

中文翻译：

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优化的 SnO2 制备和相干中间层可增强电荷动力学和高效钙钛矿光伏发电


致密、均匀和共形的电子传输层（ETL）将在很大程度上促进电荷分离和提取。本文采用混合酸（盐酸和硝酸）调节制备工艺，提高材料利用率，通过水热法制备氧化锡（SnO2）纳米晶胶体。 Sn源的完全溶解可以提高纯度，产生均匀的前驱体，减小晶粒尺寸并提高薄膜覆盖率。经证实，通过将 Cl 键合的 SnO2 薄膜与含 Cl 的钙钛矿前体耦合，可以在 SnO2 ETLs/钙钛矿界面处形成连贯的中间层。这种薄的相干中间层将大大减少界面陷阱，增强载流子的快速提取，并阻止电荷复合。 (PEO)120-(PPO)30的均匀聚合物相将用于钝化钙钛矿薄膜晶界处的陷阱，进一步提高光伏性能。钙钛矿太阳能电池实现了最大能量转换效率（23.17%，VOC为1.153 V，JSC为24.75 mA cm−2，FF为0.812）。通过相关表征技术确定电荷分离、提取和复合动力学（电荷动态过程）。功能化的SnO2-ETL和形成的相干中间层将提供一种简单的策略来有效减少界面陷阱、增强电荷提取并促进钙钛矿太阳能电池的开发。