Enhanced photovoltaic performance of P3HT:PCBM cells by modification of PEDOT:PSS layer

In this study, the doped poly(3,4-ethylene dioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) film was introduced as an anode buffer layer into the poly(3-hexylthiophene) (P3HT):[6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM) system for organic photovoltaic devices (OPVs). The doped PEDOT:PSS films were prepared by (1) mixing of PEDOT:PSS solution with ethylene glycol (EG) solvent (referred as mixing) or by (2) dipping the PEDOT:PSS-coated film into the EG solution (referred as dipping). The devices with the doped PEDOT:PSS layers showed significantly increased photovoltaic performanes upto 4.57% compared to the pristine P3HT:PCBM cells (1.27%), which can be explained by the increased conductivity of the doped PEDOT:PSS layer. The device performance of P3HT:PCBM cells showed a strong relationship with the film conductivity of PEDOT:PSS buffer layer and the surface morphology of the films.