Design And Research Of Zinc Oxide Organic Polymer Photovoltaic Cells

With the global energy crisis increasing serious, solar energy as an importantclean energy has got more and more attention. The inorganic semiconductorphotovoltaic cell has mature technology and high conversion efficiency, occupied themain position of the PV market. However, its high production costs limited itswidespread application. As a new generation, organic polymer photovoltaic cell hasthe characteristics of low cost, flexible, simple fabrication process, can be prepared bya large area, so the organic photovoltaic cells has been concerned widely. Thephotoelectric conversion efficiency of organic photovoltaic cells is low, which becamethe technique bottleneck to limit its widely used. How to improve the conversionefficiency of organic photovoltaic cell has become a hot research.In this paper, the principles of organic photovoltaic effect and the mainperformance parameters of photovoltaic cells were described in detail, and based onthis, we designed a Donor/Acceptor type heterojunction polymer photovoltaic cells.According to the principles of organic photovoltaic effect and based on the opticalinterference effects in thin film and diffusion theory, we simulate the light absorptionand exciton diffusion, which are the two main processes limit photovoltaic conversionefficiency. And we established the function between the layer thickness ofphotovoltaic cells and exciton concentration, photocurrent, external quantumefficiency. Then the analysis of simulation results show that the different filmthickness and exciton diffusion length have different influence on photocurrent andexternal quantum efficiency. The length of exciton diffusion longer, the generatedphotocurrent larger, and the film thickness can be optimized so that the photocurrentreaches its maximum value.ZnO is an important semiconductor material with wide band gap. Due to itsexcellent optical and electrical properties, it has been widely used in many areas.Based on the properties of ZnO materials and research results, we introduced it intothe structure of organic polymer photovoltaic cell. We designed two polymer photovoltaic cell structures with ZnO, and then established the charge-transfer modelaccording to the charge transfer theory, and established the equivalent circuit ofphotovoltaic cells. According to the simulation, we can see that the performance ofphotovoltaic cell has been greatly improved after ZnO being added. Finally, weanalyze the role ZnO played in the photovoltaic cells, and provide an important way toimprove the conversion efficiency of photovoltaic cells.