Influence of graphene oxide interlayer on PCE value of polymer solar cells

The main goal of the paper was investigation of influence of graphene oxide (GO) interlayer position on power conversion efficiency (PCE) of polymer solar cells. Graphene oxide was prepared by modified Hummers method and characterized by Raman spectroscopy and atomic force microscopy (AFM). The photovoltaic properties of devices based on poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) such ITO/PEDOT:PSS/P3HT:PCBM (1:1, w/w)/GO/Al, ITO/GO/P3HT:PCBM (1:1, w/w)/PEDOT:PSS/Al and ITO/GO/P3HT:PCBM (1:1, w/w)/GO/Al were investigated. As reference device ITO/PEDOT:PSS/P3HT:PCBM (1:1, w/w)/Al was applied. Photovoltaic devices were investigated under an illumination of 100 mW/cm2 (AM1.5G) and in dark. For the constructed devices impedance spectroscopy characteristics were analyzed. Among investigated devices with GO interlayer the best value of power conversion efficiency (PCE = 0.47%) was found for the device ITO\PEDOT:PSS\P3HT:PCBM\GO\Al. The devices comprising PEDOT:PSS with P3HT:PCBM and lack of GO layer showed the best photovoltaic parameters such as a Voc of 0.47 V, Jsc of 7.86 mA/cm2, FF of 0.37, and PCE of 1.38%.