Study About Influences Of The Recombination Process On The Performance Of Organic Solar Cells

As the economy of humanity develop, a large of energy consumption also makes the energy crisis and the pollution of environment has become increasingly serious, which runs counter to the theme of world development. It is a promising option for organic solar cells because of its low cost, flexible substrates, large-scale production. The power conversion efficiencies(PC E) of organic solar cells have made great progress. Meanwhile, the advent of various increasing mature methods of making process for organic thin film is a beneficial guarantee for the production of organic solar cells. To solve the problems of energy and achieve the sustainable development of economic, people have to exploit renewalbe energy on a large scale relying on science technology. The main work as following:Firstly, recombination mechanisms of the bulk heterojunction(BHJ) organic solar cells and charge transfer state(CT) are discussed, then equivalent circuit of organic solar cells is established and Silvaco simulation software is used to get the output characteristics of the device.Secondly, in order to study the CT states losses in the organic solar cells further and CT states recombination model is adopted to ontology basic electrical of the heterojunction organic solar cells, includ ing different carrier current density distribution in the organic layer when open level distribution, energy distribution, etc. We also get the velocities of the electrons and holes flowing out of the device, the velocity of the CT states generation in the device, recombination rate of geminate recombination(GR) and the velocity of CT states loss caused by current loss.Finally, influences of the bimolecular recombination(BR) and geminate recombination on the performance of organic solar cells are studied in the paper and influences of short-circuit current, open circuit voltage, fill factor and energy conversion efficiency on the performance of organic solar cells are obtained. Therefore the contrast research on GR and BR can be more clearly recognized that the influence level of two kinds of recombination mechanism on the performance of organic solar cells. In addition, organic solar cells equivalent circuit resistances are studied and we can get that bimolecular recombination and geminate recombination how to influence the series resistance and shunt resistance. In addition, the decomposition rate of CT states is calculated under the different intensity of bimolecular recombination and geminate recombination.