Efficient and stable perovskite solar cells based on functional graphene-modified P3HT hole-transporting layer

Organic-inorganic perovskite solar cells have recently emerged at the forefront of photovoltaics research. With the focus mainly on efficiency, the aspect of mobility and stability has so far not been thoroughly addressed. In this paper, we identify mobility as a fundamental weak point of perovskite solar cells, and demonstrate a facile approach to enhance the hole mobility and conductivity by introducing the highly dispersed graphene in P3HT as the hole transporting layer. With this composite structure, we achieve power conversion efficiencies of up to 13.82%. Moreover, we observe excellent stability based on the P3HT/graphene layer due to its good hydrophobicity.