Enhanced stability in perovskite solar cellsviaroom-temperature processing

Perovskite solar cells (PSC) have undergone rapid development in recent years due to their excellent photovoltaic performance. To attain desirable crystallization in perovskites, thermal annealing is widely adopted, although this does simultaneously introduce unfavourable degradation channelsviathe formation of defects. Here, we propose an illumination-assisted room-temperature process to replace traditional thermal annealing. We show that, using this strategy, similar power conversion efficiencies to those obtained with thermal annealing were obtained. Avoiding the negative effects that are induced by thermal treatment of the materials, the room-temperature-processed devices exhibit an impressive shelf stability, with no obvious degradation after 166 days. The results demonstrated in this work provide the opportunity to achieve room-temperature-annealed PSCs without compromising their stability toward the realistic application of PSC-based photovoltaic techniques.