Research On High Efficiency Flexible Dye-Sensitized Solar Cells

It is well known that fossil fuels are inevitably vanishing and have constantly brought about negative effects on climate, environment and human health. Solar energy could replace them as a renewable, low-cost and clean energy source. A new type of photoelectric cells using clean solar energy is Dye-sensitized Solar Cells (DSCs), among which the research of flexible DSCs is playing an important role in photovoltaic industry in pursuit of the new application and low cost. This paper described the preparation conditions of high efficiency flexible DSCs, and also explored the design, assembly and performance test of large-area flexible DSC.Firstly, the preparation of flexible DSCs under low-temperature was optimized. A new TiO2 paste was prepared and the effective methods of coating and reinforcing TiO2 film for fabricating photoanodes were explored. Moreover, a transparent flexible counter electrode was prepared by chemical reduction method for the first time. All-transparent and all-flexible DSCs could be assembled. Especially, we obtained the optimized such DSC with an efficiency of 3.3% by adding 6.5% butyl titanate (TBT) in the paste and treating the TiO2 film by ultrasound 20 s. In addition, we designed an all-spray technique for preparing flexible DSC which was suitable for industrial production.Secondly, a novel transfer method was employed to fabricate high efficient photoanodes. High-temperature sintered TiO2 films were transferred to the flexible substrate with poor thermostability creatively. The TBT treatment can effectively solve the dislocation problem brought about by transfer method and so that improve the stability and mechanical properties of TiO2 film. The highlight of this study was that all-transparent and all-flexible DSC fabricated by the friction-transfer technique showed a high conversion efficiency of 5.7%, which increased by ca.73% compared to that prepared by the low-temperature sintering, as well as 25% higher than compression method considered as the most effective means of improving the conversion efficiency of flexible DSC previously.Finally, the large-area flexible DSCs with the active area of 1.04 cm2 and 2.08cm2 were designed and developed based on the preparation of small-area DSCs for laboratory research. We gradually improve the photocurrent and fill factor of the large-area flexible DSCs.