Polymer-fullerene derivative bulk heterojunction (BHJ) organic photovoltaic cell (OPV) is one of the encouraging devices to harvest solar energy where transport layers carry the momentous role in performance and stability. In this work, the effect of C60 as an electron transport layer in a BHJ device composed of Poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-Phenyl-C61-butyric acid methyl ester (PCBM) is investigated by impedance spectroscopy (IS) and modelled using circuit models – the transmission circuit (TC) model and electrochemical polarization model. The effective lifetime and mobility of carriers were also extracted. It is seen that the fullerene C60 transport layer effectively reduces bulk resistance with biasing voltage.