Figure 6

Current–voltage characteristics of hole-only devices FTO/ZnCo2O4 NPs or PEDOT:PSS/Ag and electron-only device FTO/TBABF4-doped PC61BM/PEI/Ag.

Current–voltage characteristics of hole-only devices FTO/ZnCo2O4 NPs or PEDOT:PSS/Ag and electron-only device FTO/TBABF4-doped PC61BM/PEI/Ag.