Low-loss contacts on textured substrates for inverted perovskite solar cells

Inverted perovskite solar cells (PSCs) promise enhanced operating stability compared to their normal-structure counterparts. To improve efficiency further, it is crucial to combine effective light management with low interfacial losses. Here we develop a conformal self-assembled monolayer as the hole-selective contact on light-managing textured substrates. Molecular dynamics simulations indicate cluster formation during phosphonic acid adsorption leads to incomplete SAM coverage. We devise a co-adsorbent strategy that disassembles high-order clusters, thus homogenizing the distribution of phosphonic acid molecules, thereby minimizing interfacial recombination and improving electronic structures. We report a lab-measured power-conversion efficiency (PCE) of 25.3% and a certified quasi-steady-state PCE of 24.8% for inverted PSCs, with a photocurrent approaching 95% of the Shockley-Queisser maximum. An encapsulated device having a PCE of 24.6% at room temperature retains 95% of its peak performance when stressed at 65°C and 50% relative humidity following > 1000 hours of maximum power point tracking under 1-sun illumination.倒置钙钛矿太阳能电池（PSCs）相较于正置结构的同类器件，具备更优异的运行稳定性。为进一步提升器件效率，将高效光管理与低界面损耗相结合至关重要。在此，我们在具有光管理功能的织构化衬底上制备了共形自组装单分子层，将其用作空穴选择性接触层。分子动力学模拟结果显示，膦酸吸附过程中形成的团簇会导致自组装单分子层（self-assembled monolayer, SAM）覆盖不完全。我们设计了一种共吸附剂策略，可拆解高阶团簇，从而使膦酸分子的分布更均匀，进而抑制界面复合并优化电子结构。我们报道了倒置钙钛矿太阳能电池的实验室测试光电转换效率（power-conversion efficiency, PCE）达25.3%，经认证的准稳态光电转换效率（PCE）为24.8%，其光电流接近肖克利-奎伊瑟极限（Shockley-Queisser maximum）的95%。在室温下光电转换效率达24.6%的封装器件，在经历超过1000小时的1个太阳光照下的最大功率点跟踪测试后，于65℃、50%相对湿度的应力条件下仍保留了其峰值性能的95%。