Surface Plasma Effect On The Study Of The Influence Of The Organic Thin Film Solar Cell Performance

Due to the advantages such as low cost, light weight, thin thickness, and highflexibility, thin film organic solar cell has attract high attention of researchers. Howeverbecause of the contradiction between the poor absorption and low carrier mobility, thepower conversion efficiency cannot improve significantly. The way to improve lightabsorption with all other factors held stand, is a problem that need addressing.Surface plasmons can scatter incident light into a distribution of light, enhance thenear-field intensities by surface plasmonic resonance, and excite propagating waveguidemodes within the active layer, and thus enhance light absorption of the device, whichbecomes a promising way to improve device performance. In our research, wefabricated Ag nanoparticles via Vacuum Vapor Deposition, and analyzed the effect ofsurface plasmon to organic solar cell. The research content of this paper includes thefollowing aspects:The fabrication of Ag nanoparticles via Vacuum Vapor with different Ag layerthickness, and analyze of the absorption enhancement with the thickness of Ag layer.Because the diameter of Ag NPs increases, the surface plasmon resonance frequencyappears a trend of shift.By incorporating the Ag NPs into the device between the ITO anode andPEDOT:PSS layer, we fabricated the organic photovoltaic devices with the structure ofITO/Ag NPs layer (x nm)/PEDOT:PSS (20nm)/CuPc (20nm)/C60(40nm)/Bphen (5nm)/Ag (100nm), where x=0,1,2,3,4, respectively. When x=2the PCE of the deviceincrease from1.73%to2.20%. We assume that with the incorporation of Ag NPs,surface plasmon scatters the incident light and enhance the near-field intensity, whichimprove light absorption of organic active layer, and thus improve short circuit, whichfinally lead to the improvement of PCE.Based on P3HT:PCBM polymer solar cell, we incorporate Ag into Bphen cathodeblocking layer, and fabricated polymer solar cells with the structure of ITO/PEDOT:PSS (20nm)/P3HT:PCBM (200nm)/Bphen (5nm)/Ag NPs layer (x nm)/Bphen (5nm)/Ag (100nm), where x=0,1,2,3,4, respectively. When x=2nm, the device performance improved most significantly. We explained the improvement with “hot”exciton theory.