Efficiency enhancement of perovskite solar cells based on graphene-CuInS2 quantum dots composite: The roles for fast electron injection and light harvests

A high performance perovskite solar cell based on graphene-CuInS2 QDs composite was fabricated. And an improved power conversion efficiency of 17.1% is achieved. The light harvests and electron injection in graphene-CuInS2 QDs composite based solar cell was quite enhanced and facilitated with the charge transfer time of only 9.3 ns. After the deep investigation, we proposed four possible charge transfer processes for the MAPbI3/graphene-CuInS2 QDs based solar cells for the explaining of high inner photocurrent conversion efficiency. Besides, the graphene-CuInS2 QDs based solar cells have rather high reproducibility and air stability. Our results demonstrates that the graphene-CuInS2 QDs composite is excellent photovoltaic materials for fabrication of high performance solar cells.