In this study, P3HT:PCBM polymer-based solar cell devices with TiO2 and ZnO electron selective layers were separately investigated to compare effects of metal oxide layer in the inverted-type polymer solar cell structures. R.f. magnetron sputtering technique was used to fabricate highly oriented polycrystalline TiO2 and ZnO thin film layers onto FTO-coated glass substrates. The surface morphology, structural and optical properties of TiO2 and ZnO electron selective layers were studied by performing X-ray diffraction (XRD), confocal Raman spectroscopy, transmittance spectra and Atomic Force Microscope (AFM). Photovoltaic performance of inverted-type polymer solar cell based on Poly (3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-Phenyl C61 butyric acid methyl ester (PCBM) with different electron selective layers was executed to analyze the effects of TiO2 and ZnO thin film layers on the power conversion efficiency (PCE) value of inverted polymer solar cell (IPSC) devices. Produced devices with TiO2 and ZnO thin film indicated the best device performance with maximum PCE values of 2.88 and 3.49%, respectively.