Fabrication And Characterization Of Organic Solar Cells Based On Polymers And Small Moleculars

In recent years, the researches on organic solar cells have received considerable attention, due to their advantageous properties, such as low cost, light weight, mechanically flexible, easy fabrication and wide choice of component materials. The effect of upside-down drying treatment on the organic solar cells based on poly (3-hexylthiophene)(P3HT):[6,6]-phenyl-C61-butyricacid methylester (PCBM) blend was investigated, and effects of different treatments on the devices were also discussed. At the same time, we did experimental exploration of PMHJ structure devices based on small molecule materials. The works are listed as following:1, Multiple devices with the structure consisted of ITO/PEDOT:PSS/P3HT:PCBM/Ca/Al have been fabricated. Effects of different drying treatments on the device performance were systematically investigated. With an upside-down treatment of the wet layer in the drying process, the PCE of the device was apparently improved compared to the corresponding reference device. Compared to the normal drying, the up-side-down drying has a greater impact on the micro-structure of active layer by SEM and AFM characterization. The polymerization and orientation of the active layer became better. Moreover, up-side-down drying treatment shows efficient for all the devices with different thickness of active layers.2, We systematically studied the effect of different annealing temperature and time on device performance based on P3HT:PCBM. The results showed that in the laboratory,120℃annealing for15minutes enabled the device to achieve the best performance. The impact of annealing on the surface morphology and device microstructure was investigated by cross-sectional SEM and AFM. Thermal annealing can further promote the up-side-down drying optimization.3, Growth conditions of thin-film for common photovoltaic materials such as pentacene, CuPc and fullerenes were explored by a roller vacuum evaporation system, and film morphologies were characterized by AFM. High quality organic molecule film have been obtained. We fabricated the OPV devices based on pentacene and fullerene, and compared the device performance of the layer-by-layer structure with that of the PMHJ structure. Device performance with the PMHJ structure showed superior efficiency significantly. These experiments may provide the technical foundation for the organic solar cells with a large area.