▎ 摘　　要

In this communication, we report a simple method for a covalent band-forming reaction to change the hybridization of carbon atoms from sp(2) to sp(3), to introduce a band gap in pristine graphene. Graphene with well-defined functionality was synthesized, and the resulting material was soluble in organic solvent. The LUMO of functionalized graphene was below the LUMO of poly(3-hexylthiophene) (P3HT) and close to that of [6,6]-phenyl C-61-butyric acid methyl ester (PCBM), indicating its suitability as an electron acceptor for organic photovoltaic (OPV) applications. We further show the P3HT/functionalized graphene composite as the active layer in a solar cell, with device efficiency of 1.1%.