Efficient Organic Photovoltaic Devices by Using PEDOT:PSSs with Excellent Hole Extraction Ability

Abstract

We have demonstrated the poly(3-hexyl-thiophene-1,5-diyl) (P3HT):[6,6]-phenyl C61-butyric acid methyl ester (PCBM) bulk heterojunction (BHJ) organic photovoltaic (OPV) devices on various poly(3,4-ethylene-dioxythiophene):poly(styrenesulfonate) (PEDOT:PSSs). The device with PEDOT:PSS of PH 500 adding 1% dimethyl sulfoxide (DMSO) showed the best performances in term of the fill factor and power conversion efficiency (PCE) than others. The hole extraction ability of PEDOT:PSS is very important to balance between holes and electrons mobility because the carrier mobility of PCBM (similar to 10(-4) cm(2)/Vs) is higher than that of P3HT (similar to 10(-6) cm(2)/Vs) in P3HT:PCBM BHJ structure. The optimized BHJ OPV with PEDOT:PSS of PH 500 adding 1% DMSO showed a short-circuit current density of 8.92 mA/cm(2) and a PCE of 2.97%, which was nearly increased to 2.5 times than that of control device with PEDOT:PSS of P VP Al 4083.