Buried Interface Engineering Enables Efficient and 1,960-hour Isos-L-2i Stable Inverted Perovskite Solar Cells

High-performance perovskite solar cells (PSCs) typically require interfacial passivation, yet this is challenging for the buried interface, owing to the dissolution of passivation agents during the deposition of perovskites. Here, we overcome this limitation with in-situ buried interface passivation – achieved via directly adding a cyanoacrylic acid-based molecular additive, namely BT-T, into the perovskite precursor solution. Classical and ab-initio molecular dynamics simulations reveal that BT-T spontaneously may self-assemble at the buried interface during the formation of the perovskite layer on a nickel oxide hole transporting layer. The preferential buried interface passivation results in facilitated hole transfer and suppressed charge recombination. In addition, residual BT-T molecules in the perovskite layer enhance its stability and homogeneity. We report a power-conversion efficiency (PCE) of 23.48% for 1.0 cm2 inverted-structure PSCs. The encapsulated PSC retains 95.4% of its initial PCE following 1,960-hour maximum power point tracking under continuous light illumination at 65°C (i.e., ISOS-L-2I protocol). Our demonstration of operating-stable PSCs under accelerated ageing conditions represents a step closer to the commercialization of this emerging technology.高性能钙钛矿太阳能电池（perovskite solar cells, PSCs）通常需要界面钝化，但对于埋置界面而言，这一过程极具挑战——原因在于钙钛矿沉积过程中钝化剂会发生溶解。本研究通过原位埋置界面钝化策略克服了这一局限：具体做法是将氰基丙烯酸类分子添加剂BT-T直接添加至钙钛矿前驱体溶液中。经典分子动力学与从头算分子动力学模拟结果表明，在氧化镍空穴传输层上制备钙钛矿层的过程中，BT-T可自发在埋置界面处自组装。这种针对性的埋置界面钝化可促进空穴传输并抑制电荷复合。此外，钙钛矿层中残留的BT-T分子可提升薄膜的稳定性与均匀性。本研究制备的1.0 cm²反式结构钙钛矿太阳能电池实现了23.48%的光电转换效率（power-conversion efficiency, PCE）。经过65℃下连续光照1960小时的最大功率点跟踪测试（即ISOS-L-2I标准协议）后，封装后的钙钛矿太阳能电池仍保留其初始光电转换效率的95.4%。本研究在加速老化条件下实现了运行稳定的钙钛矿太阳能电池，为这一新兴技术的商业化应用迈出了重要一步。