Metal halide perovskite solar cells (PSCs) have made a great progress in recent years, however, charge recombination and losses at interfaces between the different layers restrict their performance. In the present work, we devised an efficient method that not only passivates the interfacial traps but also enhances charge extraction of the PSC. The chlorobenzene with the addition of Poly(3-hexylthiophene) (P3HT) is used as antisolvent during the spin coating process of the wet perovskite film. In this way, P3HT molecules permeate along perovskite grain boundaries to fill the pinholes and repair interfacial defects of the perovskite film. In addition, the valence band (VB) of the surface of the perovskite layer is thus tuned to form an energy level better aligned with the hole transport layer (HTL). Such a gradient heterojunction structure (GHJ) layer containing P3HT and perovskite provides a rapid channel for hole migration and improves carrier extraction efficiency. The power conversion efficiency of the champion solar cell is up to 20.0% with an open-circuit voltage of 1.18 V, a short-circuit current density of 22.2 mA/cm² and a fill factor of 76.2%. Due to the hydrophobicity of the mixture layer, the long-term stability of the devices has been improved as well.

近年来，金属卤化物钙钛矿太阳能电池（PSC）取得了长足进步，但是，电荷复合以及不同层之间界面的损耗限制了它们的性能。在当前的工作中，我们设计了一种有效的方法，该方法不仅可以钝化界面陷阱，而且可以增强PSC的电荷提取。在湿钙钛矿薄膜的旋涂过程中，添加了聚（3-己基噻吩）（P3HT）的氯苯用作抗溶剂。通过这种方式，P3HT分子沿钙钛矿晶界渗透，填充针孔并修复钙钛矿膜的界面缺陷。另外，钙钛矿层表面的价带（VB）因此被调节以形成更好地与空穴传输层（HTL）对准的能级。包含P3HT和钙钛矿的这种梯度异质结结构（GHJ）层为空穴迁移提供了快速通道，并提高了载流子提取效率。在1.18 V的开路电压，22.2 mA / cm的短路电流密度下，冠军太阳能电池的功率转换效率高达20.0％²，填充率为76.2％。由于混合物层的疏水性，器件的长期稳定性也得到了改善。