Non-fullerene Organic Photovoltaics Fabricated By Soft Porous Blade Coating

Organic photovoltaics has the advantages of low cost,thin thickness and simple process.It can also be made into flexible devices.It has become one of the most dynamic and vital research frontiers of new materials and new energy.However,the main method of preparing organic photovoltaics in the laboratory is spin coating,which wastes more materials during the preparation process and has limitations in the preparation of large-area devices.Blade coating has a fast processing speed and can realize the preparation of large-area devices,so it has the potential for commercial production.However,the commonly used methods still face problems to be solved urgently: the flow field shear rate is not high enough,the patterned preparation of organic photovoltaics devices cannot be achieved,the equipment is more complicated,and they also waste much materials.Developing the new method of blade coating which has the advantages of high material utilization rate,simple equipment,easy patterning,and compatibility with flexible substrates,while optimizing molecular arrangement and crystallinity to improve device efficiency has important significance for promoting the commercialization of organic photovoltaics.This paper proposes a new method for preparing organic photoelectric films: soft porous blade coating.The active layer of bulk heterojunction and planar diffusion heterojunction of non-fullerene organic photovoltaics was prepared by soft porous blade coating.The results of the morphology and photoelectric properties of the active layer films show that the porous microstructure of the soft porous blade coating can generate micro-scale flow with high shear rate which is conducive to inducing the orderly arrangement,crystallization and orientation of organic material molecules to improve the efficiency of devices.In addition,the soft porous blade coating does not require the meniscus to guide the solution,which facilitates the preparation and thickness control of the planar diffusion heterojunction active layer by layer by layer preparation.Through the analysis of active layer film morphology,photoelectric performance and power conversion efficiency,the influence and optimization of process conditions on active layer thickness,morphology and device photoelectric performance are studied.The power conversion efficiency of bulk heterojunction organic photovoltaics based on PM6: Y6 and PTQ10:IDIC systems prepared by soft porous blade coating reaches 14.75% and 11.85%,and the efficiency of planar diffusion heterojunction organic photovoltaics reaches 14.29% and 11.79%,which are significantly better than the corresponding spin coating devices.Soft porous blade coating has the advantages of simple process,low cost,high solution utilization rate,easy patterning and large-area preparation.It is universal in the preparation of organic photoelectric films and can be used as an effective method for preparing high-performance flexible electronic devices by printing method.