This study presents experimental evidence of the dependence of non-radiative recombination processes on the electron–phonon coupling of perovskite in perovskite solar cells (PSCs). Via A-site cation engineering, a weaker electron–phonon coupling in perovskite has been achieved by introducing the structurally soft cyclohexane methylamine (CMA⁺) cation, which could serve as a damper to alleviate the mechanical stress caused by lattice oscillations, compared to the rigid phenethyl methylamine (PEA⁺) analog. It demonstrates a significantly lower non-radiative recombination rate, even though the two types of bulky cations have similar chemical passivation effects on perovskite, which might be explained by the suppressed carrier capture process and improved lattice geometry relaxation. The resulting PSCs achieve an exceptional power conversion efficiency (PCE) of 25.5% with a record-high open-circuit voltage (V_OC) of 1.20 V for narrow bandgap perovskite (FAPbI₃). The established correlations between electron–phonon coupling and non-radiative decay provide design and screening criteria for more effective passivators for highly efficient PSCs approaching the Shockley–Queisser limit.

这项研究提供了钙钛矿太阳能电池（PSC）中非辐射复合过程对钙钛矿电子-声子耦合依赖性的实验证据。通过A位阳离子工程，通过引入结构较软的环己烷甲胺（CMA ⁺ ）阳离子，在钙钛矿中实现了较弱的电子-声子耦合，与钙钛矿相比，它可以作为阻尼器来减轻晶格振荡引起的机械应力。刚性苯乙基甲胺 (PEA ⁺ ) 类似物。尽管两种类型的大体积阳离子对钙钛矿具有相似的化学钝化作用，但它表现出显着较低的非辐射复合率，这可能是通过抑制载流子捕获过程和改善晶格几何弛豫来解释的。由此产生的 PSC 实现了 25.5% 的卓越功率转换效率 (PCE) ，窄带隙钙钛矿 (FAPbI ₃ )的开路电压 ( _VOC )达到创纪录的 1.20 V。电子声子耦合和非辐射衰变之间已建立的相关性为更有效的钝化剂提供了设计和筛选标准，以实现接近肖克利-奎瑟极限的高效PSC。