The photovoltaic performance of non-fullerene organic solar cells (OSCs) is essentially determined by the presence of charge traps. However, their exact distributions in OSCs have remained unclear. Here, we report the successful profiling of spatial and energetic distributions of trap states via the drive-level capacitance profiling (DLCP) method. Our DLCP results unveil that the trap densities at device interfaces are 1 to 2 orders of magnitude greater than those of the film interior, and improving film crystallinity helps reduce trap density. Furthermore, the DLCP method enables operando monitoring of trap evolution during OSC operation, which reveals that trap evolution is strongly correlated with film morphology stability. The OSCs with stable morphology show minimal changes in trap distributions and can operate for 500 h without significant efficiency loss. With this method, we establish the correlations between trap distributions/evolution and device efficiency/stability and provide insightful guidance toward more efficient and stable OSCs.

中文翻译：

---

非富勒烯有机太阳能电池中陷阱态的分布和演变


非富勒烯有机太阳能电池 （OSC） 的光伏性能主要取决于电荷陷阱的存在。然而，它们在 OSC 中的确切分布仍不清楚。在这里，我们报告了通过驱动级电容分析 （DLCP） 方法成功分析陷阱状态的空间和能量分布。我们的 DLCP 结果显示，器件界面处的陷阱密度比薄膜内部的陷阱密度高 1 到 2 个数量级，提高薄膜结晶度有助于降低陷阱密度。此外，DLCP 方法可以对 OSC 操作期间的陷阱演变进行原位监测，这表明陷阱演变与薄膜形态稳定性密切相关。形态稳定的 OSCs 在陷阱分布中表现出最小的变化，并且可以运行 500 小时而不会显着的效率损失。通过这种方法，我们建立了陷阱分布/演变与设备效率/稳定性之间的相关性，并为更高效、更稳定的 OSC 提供了有见地的指导。