An Alternative Hole Transport Layer for Both ITO- and Graphene-Based Organic Solar Cells

A new type of hole transport layer, polythiophene derivative, for organic solar cells is introduced, which shows similar transparency and good wettability for both indium tin oxide (ITO) and graphene compared to poly(3,4- ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). Efficient graphene-based organic solar cells are demonstrated and shows power conversion efficiencies approaching those of ITO-based reference devices using the proposed hole transport layerclose1