Graphene enabled all-weather solar cells for electricity harvest from sun and rain
Future solar cells are expected to generate electricity under all weather conditions. To address this profound issue, we take the first step to produce solar cells that can generate electricity under both rainy and sunny conditions. In the current study, a bifunctional solar cell realizing photoelectric conversion under solar irradiation along with the electric signals by dropping raindrops was produced by integrating a monolayer graphene with a solar cell, yielding a maximal photoelectric conversion efficiency of 7.69% under AM1.5 irradiation as well as a current of 0.66 μA per raindrop and a voltage of 61.8 μV per raindrop by simulated raindrops. Owing to the optical loss across the monolayer graphene, the solar cell architecture was optimized, yielding a solar cell efficiency of 9.14% as well as a current of a few microamps per raindrop and a voltage of tens of microvolts per raindrop. Moreover, the newly launched solar cell has good stability under the persistent dropping of simulated rain. The current work can also extend our knowledge of advanced all-weather solar cells.