Funetionalized Graphene/Ag nanoparticles Bi-layer to enhance the efficiency of polymer solar cells

摘要

We prepared graphene oxide (GO) by a modified Hummer's method, and synthesized octylamine funetionalized graphene (F-GNS) using long-chain octylamine as the functionalization agent. We synthesized oleic acid silver nanoparticles (OA-Ag) by the redox method. We investigated the effect of incorporating F-GNS/OA-Ag bi-layer between polyethylene dioxythiophene) (PEDOT)-polystyrene sulfonic acid (PSS) (PEDOT:PSS) hole transport layer (HTL) and active layer (P3HT:PC_(71)BM =1:1 weight ratio) on the photovoltaic performance. The cell structure was glass/IT0/PED0T:PSS/F-GNS/OA-Ag/P3HT: PC_(71)BM/Ca/Al. Four concentrations of F-GNS N-methyl pyrrolidone (NMP) solution of 0.05, 0.1, 0.3 and 0.5 mg/ml were prepared. We used the UV-Vis, SPM, FE-SEM and solar simulator to measure the absorbance, roughness, surface morphology, and power conversion efficiency (PCE), respectively. From these results, we found that the short circuit current density(J_(sc)) and PCE of the cells with F-GNS/OA-Ag are always higher than those of cell without F-GNS/OA-Ag. The cell with 0.1 mg/ml F-GNS/OA-Ag bi-layer had the highest J_(sc) of 8.51 mA/cm~2, an increase of 32% and the highest PCE of 2.96%, an increase of 28% compared to the reference cell. These improvements were due to the high carrier mobility of graphene.