▎ 摘　　要

Four different graphene films were synthesized via chemical vapor deposition by using acetonitrile with feed rates of 0.01, 0.02, 0.04, and 0.06 mL/min. Heterojunction solar cells were assembled by transferring as-synthesized graphene films onto n-Si. Solar cells based on graphene samples produced at 0.01, 0.02, 0.04, and 0.06 mL/min demonstrate power conversion efficiencies of 2.26%, 2.10%, 1.02%, and 0.94%, respectively. When HNO3 was used to dope the graphene films, the corresponding photovoltaic efficiencies were increased to 4.98%, 4.19%, 2.04%, and 1.74%, respectively. Mechanism for the improved efficiency of graphene/Si heterojunction solar cells was also investigated.