The effect of interlayer on the performance of a poly[2-methoxy-5-(3',7'-dimethylocty)-1,4-phenylenevinylene]
(MDMO-PPV)/1-(3-methoxycarbony 1)-propy1-1 phney1-(6-6)C61 (PCBM) composite solar cell device has been
reported recently. Herein we report bulk heterojunction organic solar cell with efficiency enhanced by interlayer made
from blend film of regioregular poly(3-hexylthiophene)(P3HT) and PCBM. The interlayer, poly(9,9-dioctylfluorene)-co-N-(1,4-butylphenyl)diphenylamine)(TFB), was inserted between the poly(3,4-ethylene dioxythiophene)-poly(styrene
sulfonic acid)(PEDOT:PPS) and the active layer. With the interlayer, the efficiency was enhanced due to the increased
short circuit current density (Jsc), open circuit voltage (Voc) and fill factor (FF) obtained from testing and calculation.
According to the analysis, the interlayer TFB, acting as an effective exciton-blocking layer, prevented the severe
quenching of radiative excitons between the interface of PEDOT:PSS. In the study, the interlayer increased Jsc from
0.891 mA/cm2 to 1.025 mA/cm-2, Voc from 0.478 V to 0.526 V, and FF from 0.327 to 0.416, under illumination by
white light from a solar simulator with an incident intensity of 80mW/cm2; the power conversion efficiency of the
device reached higher value 0.280% comparing with 0.174% with no interlayer.