ACS Appl Mater Interfaces. 2018 Jun 20;10(24):20578-20590. doi: 10.1021/acsami.8b05560. Epub 2018 Jun 6.
Appropriate electron transport layers (ETL) are essential in perovskite solar cells (PSCs) with high power conversion efficiency (PCE). Herein, a TiO/ZnO/C trilayer fabricated on a transparent fluorine-doped tin oxide (FTO) glass substrate is used as a compound ETL in planar PSCs. The trilayer shows positive effects on both perovskite synthesis and device performance. The ZnO layer assists growth of CHNHPbICl ( x ≈ 0) annealed at a lower temperature and with a shorter time, which is due to a more rapid and easier decomposition of the intermediate CHNHPbCl phase in the growth of CHNHPbICl . All three materials in the trilayer are important for obtaining PSCs with a high PCE. ZnO is critical for enhancing the open circuit voltage by ensuring proper energy alignment with the TiO and C layers. C enhances carrier extraction from the CHNHPbICl layer. TiO eliminates charge recombination at the FTO surface and ensures efficient electron collection. The best-performing PSC based on the TiO/ZnO/C electron transport trilayer features a PCE of 18.63% with a fill factor of 79.12%. These findings help develop an understanding of the effects of ZnO-containing ETLs on perovskite film synthesis and show promise for the future development of high-performance PSCs with compound ETLs.
在具有高功率转换效率 (PCE) 的钙钛矿太阳能电池 (PSC) 中，合适的电子传输层 (ETL) 至关重要。在此，在透明掺氟氧化锡 (FTO) 玻璃基底上制备的 TiO/ZnO/C 三层膜被用作平面 PSC 的复合 ETL。该三层膜对钙钛矿的合成和器件性能都有积极的影响。ZnO 层有助于在较低温度和较短时间下退火的 CHNHPbICl（x≈0）的生长，这是由于在 CHNHPbICl 的生长中，中间的 CHNHPbCl 相更容易快速分解。该三层膜中的所有三种材料对于获得具有高 PCE 的 PSC 都很重要。ZnO 对于通过确保与 TiO 和 C 层的适当能量对准来提高开路电压至关重要。C 增强了从 CHNHPbICl 层提取载流子的能力。TiO 消除了 FTO 表面的电荷复合，并确保了有效的电子收集。基于 TiO/ZnO/C 电子传输三层膜的性能最佳的 PSC 的 PCE 为 18.63%，填充因子为 79.12%。这些发现有助于深入了解含 ZnO 的 ETL 对钙钛矿薄膜合成的影响，并为具有复合 ETL 的高性能 PSC 的未来发展提供了希望。
