Organic solar cells (OSCs) with p-i-n structure have achieved rapid progress in efficiency recently. However, the p-i-n structure suffers from inferior stability owing to the hole-transporting layers (HTLs) that usually encounter unfavorable phase separation or insufficient anode coverage under aging. Herein, we develop a subtle strategy that integrates self-assembled monolayer (SAM) and polyoxometalate (POM) into an intimately intercalating composite as HTL. This sequentially deposited composite (SDC) shows a unique distribution pattern, with SAM enriched at the bottom and POM functioned as both void-filler and top-surface passivator, enabling improved surface contact. Moreover, the formation of multiple doping pathways increases the charge extraction in OSCs. The SDC-HTL strategy not only results in a much higher device efficiency, but it significantly impedes the photovoltage and fill-factor degradation in p-i-n OSCs under multiple stresses. This work demonstrates the superiority of integrating multiple ultra-thin HTLs for improving the interfacial contact between functional layers, thus addressing the instability in OSCs.

中文翻译：

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多金属氧酸盐团簇与自组装单层的集成，用于高效、鲁棒的有机太阳能电池

Pin结构的有机太阳能电池（OSC）最近在效率方面取得了快速进步。然而，由于空穴传输层（HTL）在老化时通常会遇到不利的相分离或阳极覆盖不足，因此pin结构的稳定性较差。在此，我们开发了一种巧妙的策略，将自组装单层 (SAM) 和多金属氧酸盐 (POM) 集成到紧密嵌入的复合材料中，如 HTL。这种顺序沉积复合材料 (SDC) 显示出独特的分布模式，SAM 在底部富集，POM 充当空隙填充剂和顶面钝化剂，从而改善表面接触。此外，多种掺杂途径的形成增加了OSC中的电荷提取。 SDC-HTL 策略不仅可以实现更高的器件效率，而且可以显着阻止多重应力下引脚 OSC 的光电压和填充因子下降。这项工作证明了集成多个超薄 HTL 在改善功能层之间的界面接触方面的优越性，从而解决了 OSC 的不稳定性。