Abstract: Poor electron and hole transfer and high carrier recombination are critical problems for realizing
commercial applications of PSCs ( Polymer Solar Cells). We introduce PFO ( poly (9,9-dioctylfluorenyl-2,
7-diyl)) as a TiO 2 hybrid interface modification layer to enhance the performance of inverted PSCs. Surface
morphology and work function measurement demonstrated that PFO interlayer eliminated the defects and traps
from TiO 2 surface and acted as an efficient charge transport matrix, resulting in enhanced charge carrier transfer
between the electrode and the active layer. The photocurrent and the fill factor of the PSCs are both increased,
resulting in an increased PCE(Power Conversion Efficiency) from 5. 17% to 6. 96%.

Key words: photocurrent ( J sc ), power conversion efficiency (PCE), polymer solar cells ( PSCs), interface modification