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Because organic polymer solar cells photoelectric conversion efficiency is low, through improve the design of different active material and choice methods, in order to improve the performance of the organic solar cells, alleviate the energy crisis. Graphene use sp2 heterozygous carbon atoms into keys, has the two-dimension plane structure like honeycomb, shows optical, electrical, and mechanical characteristics. When its compound with polymer can form considerable interface, improve the rate of expansion and excitons mobility, and can not cause the destruction of charge transport path bring about produce secondary gathered. Therefore, graphite is a very good choice to become receptor material in organic polymer solar cells. The content of this research as follows:1、The paper use Hummers method prepare the graphene to make sure the graphene surfaces layers and size, defect can be effectively controlled. Using SEM, TEM and AFM, polarizing microscope and Raman spectra characterized for its morphology. XRD, FT-IR is used to analyze its chemical structures. After analysis, we can make sure the graphene transverse dimensions is come to microns, thickness can achieve 1nm or so, and its surface coarse, the layer number of graphene in average is about 1-3 layer. Graphene oxide surfaces are influenced by thermodynamic fluctuation. The surface has drape, so has large specific surface area. Because graphene oxide is insoluble in organic solvents, we adopt phenyl isocyanater processing graphene oxide, graphite oxide layer reduce hydrophilic, then make it more dissolvable in organic solvents.2、This paper use P3HT as donor material, with graphene as receptor materials to make organic solar cell activity layer, prepare the structure of organic solar cell is ITO/ PEDOT:PSS/P3HT: SPFGraphene Oxide/LiF/Al, in order to improve the efficiency of solar cell device. At normal temperature, we use simulation illumination test the cell. when the graphene doping concentration is 2.5%,5%,10%,15%,the photoelectric conversion efficiency of the device were 0.05%,0.06%,0.11% and 0.1%. Photoelectric conversion efficiency increases first, then reached a peak gradually decreases.3、Through the research of graphene oxide thermo-gravimetric analysis curves, we found the relationship between the annealing temperature and weight change, and the influence of annealing temperature on the material. Device after 160℃10min,160℃20min annealing treatment, the short-circuit current, open voltage and the efficiency has been obviously increased, which the short-circuit current is increased about an order of magnitude. When the doping concentration is 10% and after 160℃10min annealing treatment, the performance of the devices is the best. The open voltage of the device is 0.92V, short-circuit current is 4.1mA/cm2, fill factor reached 0.32, the efficiency up to 1.2%.
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