The role of hydrogen in nonradiative recombination in CsPbI₃: a first-principles investigation

Defect-induced nonradiative recombination is the main factor hindering efficiency improvement in CsPbI 3 perovskite solar cells. It has been recently claimed that the unintentionally incorporated H impurity can potentially cause nonradiative losses due to the deep levels. Using first-principles approaches, we show that, as a matter of fact, the H impurity has a negligible effect on carrier recombination in CsPbI 3 due to its small nonradiative capture coefficient and low density. This insight rationalizes why the addition of hydriodic acid does not reduce carrier lifetime and could prevent acidic additives being discarded as potential candidates for assisting film growth.