PEDOT:PSS Modification by blending graphene oxide to improve the efficiency of organic solar cells

In this work, we present a simple method to modify poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) by directly blending graphene oxide (GO) into PEDOT:PSS to form (PEDOT:PSS):GO nanocomposite and it shows an enhanced conductivity than that of pristine PEDOT:PSS due to the benzoid-quinoid structure transition of PEDOT:PSS. By applying the obtained nanocomposite (PEDOT:PSS):GO film as the hole-transporting layer (HTL) in organic solar cells (OSCs) ITO/HTL/active-layer/Ca/Al, in which the active layer consists of poly(3-hexylthiophene-2,5-diyl) (P3HT):[6,6]-phenyl C₆₁ butyric acid methyl ester (PC₆₁BM) or P3HT:indene-C₆₀ bisadduct (ICBA), we found that the power conversion efficiency of these two OSCs with P3HT:PC₆₁BM and P3HT:ICBA as the active layer reached to 3.96% and 5.89%, respectively, showing correspondingly enhancement of 14.78% and 9.89% as compared with those of the control devices in which PEDOT:PSS without any modification. Therefore, PEDOT:PSS modified with GO provides an easy way to fabricate stable OSCs with high performance and low cost. POLYM. COMPOS., 39:3066–3072, 2018.