▎ 摘　　要

We report a bidirectional, treated graphene oxide electrode-based organic bulk heterojunction solar cell. The nature of interfaces in the photoactive region (between PTB7/PC71BM), charge transport, and the role of treated graphene's transparency in the device performance are investigated. Use of treated graphene reduces the sheet resistance (200-75 Omega/sq) of poly(3,4-ethylenedioxythiophene)polystyrene sulfonatethin film and improves the organic solar cell performance over a wide spectral range (250-750 nm). Due to: 1) the charge neutrality between PTB7 and PC71BM and 2) lowering of defect states in the electron collection layer, the overall solar cell power conversion efficiency (eta) reaches 8.4% +/- 0.23%; a fill factor of 69.5%, short-circuit current density of similar to 16.1 mA . cm(-2) and internal quantum efficiency of similar to 68.8%.