Room-temperature processed, air-stable and highly efficient graphene/silicon solar cells with an organic interlayer

Graphene/silicon (Gr/Si) solar cells have attracted interest for their potential in low-cost photovoltaic applications. Inserting a p-type organic hole transporting layer (HTL) in-between the Gr and Si would suppress carrier recombination and improve the performance of the solar cells. Here, we report highly stable and high-performance Gr/Si solar cells fabricated by using a room-temperature process. Spiro-OMeTAD was selected as the HTL for its novel electrical and optical properties. The employment of spiro-OMeTAD led to an impressive power conversion efficiency (PCE) of 13.02%. Moreover, our solar cells exhibit excellent stability with a PCE of similar to 11% for over four months. These results could be encouraging for the development of Gr/Si solar cells toward practical applications. Meanwhile, this work offers a universal solution for the application of organics in Gr-based optoelectronics and photovoltaics from the viewpoint of device robustness.