If you want to check out some papers on organic solar cell materials, start out with some of these page-turners!
One-Dimensional Self-Confinement Promotes Polymorph Selection in Large-Area Organic Semicondutor Thin Films
Understanding Polymorphism in Organic Semiconductor Thin Films through Nanoconfinement
Soluble n-type pentacene derivatives as novel acceptors for organic solar cells
Organic photovoltaic cells with high open circuit voltages based on pentacene derivatives