Efficiency Improvement of Heterojunction Polymer Photovoltaic Cells through Controlling the Morphology of the Polymer Film
【摘要】：正1 Results Polymer photovoltaic cells, which provide clean and renewable energy sources, have gained more and more attention. Polymer photovoltaic cells have the advantage of low fabrication cost and high mechanical flexibility. Polymers can be processed through a solution process, so that a homogeneous polymer film could be readily prepared in a large area. Recently, the light-to-electricity conversion efficiency of the polymer photovoltaic cells was improved significantly[1-2]. Polymer donor and organic acceptor are the two components in the active layer of the polymer photovoltaic cells. The photovoltaic performance is strongly dependent on morphology of the polymer donor/organic acceptor film. The dependences of the film morphology and the device performance on the temperature, solvent and ratio of the polymer donor to acceptor will be reported. Baking of the polymer film at a high temperature significantly affects the absorption and the morphology of the polymer film, which is account for the effect of baking polymer film on the photovoltaic performance. Similar effect on the polymer film morphology and absorption can be achieved by adding small amount of organic molecule into the polymer solution. The photovoltaic performance is related to the structure of the additives.