Article,
In-situ Identification of Photo- and Moisture-Dependent Phase Evolution of Perovskite Solar Cell
ACS Energy Letters, 0 (ja): null (0)
DOI: 10.1021/acsenergylett.6b00698
Abstract
Photovoltaic performance of perovskite solar cell is observed to decrease with increasing humidity, which might be attributed to the formation of hydrated intermediates and further leads to a decrease in extraction of photo-carriers. However, direct evidence of the interplay between the perovskite layer and the photovoltaic performance under operating conditions (consecutive illuminating) has not yet been reported. Herein, we investigated the degradation of perovskite solar cell under operating situations through in-situ X-ray diffraction and in-situ X-ray absorption spectroscopies, which revealed that lead hydroxide iodide (PbIOH), a new phase that hasn’t previously identified as the degradation product of perovskite solar cell, was formed as end decomposition product inside the cell. The formation of PbIOH could break the interface inside and be the key reason behind the problem of reduced cell life. This work illustrates that in operando direct observation of the photo- and moisture-induced effects can provide needed insights toward realizing stable perovskite solar cells.
