Mingwei Hao1,Yuanyuan Zhou1
Hong Kong Baptist University1
Mingwei Hao1,Yuanyuan Zhou1
Hong Kong Baptist University1
Grain-boundary groove (GBG) is an inherent microstructural feature of grain boundaries in metal halide perovskites, which has not been quantitatively studied. In this work, we leveraged high-resolution characterization methods to qualify the characteristic GBG angles and revealed their impact on properties of perovskite heterointerface and performance of PSC devices. We showed that flattening GBGs can lead to significantly enhanced optoelectronic properties, chemical stability, and most importantly opto-mechanical reliability of perovskite heterointerfaces. Highly efficient and stable perovskite solar cells are thus fabricated via the GBG optimization.