Improving Power Conversion Efficiency of P3HT/PCBM based Organic Solar Cells by Optimizing Graphene Doping Concentration and Annealing Temperature

摘要

Graphene (GN) doping concentration and annealing temperature in blended poly (3-hexylthiophene)and [6,6]-phenyl C61 butyric acid methyl ester 3HT/PCBMwith GN (P3HT/PCBM /GN) basedorganic solar cells (OSC) were investigated. Results indicate the power conversion efficiency (PCE) ofo P3HT/PCBM /GN based OSC can be efficiently increased by 3 wt% GN doping and 120 C annealing.The OSC doped with 3 wt% GN exhibited the highest PCE among OSC doped with 0~10 wt% GNo o under the same annealed condition: unannlealed status and 120 C annealing. The PCE of 120 Cannealed OSC doped with 3 wt% GN is 2.81, which is almost two times higher than that doped with 10wt% GN. Thermal desorption spectra of unannealed P3HT/PCBM /3 wt% GN show two desorptiono peaks at around 130 and 182 C resulting from water vapor. The two temperatures are close to the glasso transition temperature of PCBM and melting temperature of P3HT, respectively. The 120 C annealingon P3HT/PCBM/3 wt% GN can make both P3HT and PCBM have relatively good crystallizationo compared with unannealed status and 170 C annealing. Good crystallization makes charge carrierstransport easily in P3HT/PCBM/3 wt %GN based OSC.