As a general materials phenomenon driven by thermodynamics, grain boundary network, when extending onto the film surface or interface, can create an intriguing grooving geometry. Such formed grain-boundary grooves (GBGs) invariably influence the heterointerface microstructures in perovskite solar cells (PSCs). Herein, we present a unique, focused discussion on this prominent yet rarely studied microstructure type. In this perspective, we first illustrate the fundamental theories that govern the formation of GBGs and their dynamics. Then, we envision the effects of GBGs on carrier transport, chemical stability, and mechanical reliability of perovskite thin films. Finally, we propose possible engineering methods to tailor GBGs for PSCs with enhanced efficiency and durability.

中文翻译：

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钙钛矿太阳能电池中的晶界凹槽

作为热力学驱动的一般材料现象，晶界网络当延伸到薄膜表面或界面时，可以产生有趣的凹槽几何形状。这种形成的晶界凹槽（GBG）总是会影响钙钛矿太阳能电池（PSC）中的异质界面微观结构。在此，我们对这种突出但很少研究的微观结构类型进行了独特的、集中的讨论。从这个角度来看，我们首先阐述了控制 GBG 形成及其动力学的基本理论。然后，我们设想了 GBG 对钙钛矿薄膜的载流子传输、化学稳定性和机械可靠性的影响。最后，我们提出了可能的工程方法，为 PSC 定制 GBG，提高效率和耐用性。