The Fabrication And Research Of High-performance Large-Area Organic Solar Cells

Organic solar cells have developed rapidly in the past two years,and their efficiency has been constantly improved by the synthesis of a series of highly efficient non-fullerene acceptors.Presently,the highest efficiency single binary organic solar cell has exceeded 15%,while ternary organic solar cell and tandem organic solar cell have both exceeded 17%,which means efficiency is no longer the only factor limiting the development of organic solar cells.At present,the area of organic solar cells fabricated in the laboratory is usually less than 0.1 cm~2,and there are few studies on the fabrication of organic solar cells in large areas.Blade-coating is simple craft,low cost and high material utilization,which is more suitable for fabricating large-area devices.Therefore,in this paper,large area non-fullerenes organic solar cells with high efficiency were prepared by Blade-coating method.The main work of this paper is as follows:The first part of the work mainly includes the exploration of the scraping process parameters and the influence of the Blade-coating process on the morphology of the film and the performance of the device.In this part,we first analyzed the relationship between the film thickness and the key parameters such as blade speed,blade height and solution concentration.It is found that the blade height is positively correlated with the film thickness,and the film thickness increases roughly linearly with the increase of the blade height.The blade speed is negatively correlated with the film thickness.The faster the blade speed,the thinner the film thickness.Then,three groups of experiments were carried out aiming at figure out the influence of Blade-coating method on the morphology of the film.The additive,temperature and the type of solution were changed respectively.Then the morphology of the film was tested.The better film morphology can be obtained by Blade-coating with less additive.At the same time,appropriate substrate temperature can achieve higher device efficiency.The second part is the fabrication of large-area devices using an efficient non-fullerene system PTO2:IT-4F.Firstly,the parameters of the device were optimized under the condition of Blade-coating method.Then we designed the substrate and mask which are more suitable for large area devices and fabricated the device with an efficiency of 7.14%.However,the filling factor of the large area device was greatly attenuated.In order to solve this problem,we introduced the third element material IT-M for ternary doping,and finally obtained a high-efficiency organic solar cell of 11%.