Study On Application Of Carbon Materials In Photoanode For Dye-sensitized Solar Cells

Dye-sensitized solar cells(DSSCs) have attracted exensive research interests from scientists, due to the low-cost and easy fabrication process compared with silicon solar cells. Photoanode is one of the most important parts of the DSSCs, which is the carrier of the dye molecule and plays an important role in separation and transport electrons. Development of the photoanode with excellent composition and structure is the important research field to improve the performance of DSSCs.Nano-carbon materials have unique structural, physical property, such as high electrical conductivity and large surface area. Therefore, they are regarded as ideal electrode materials. In order to improve the efficiency of electron transmission of photoanode, this thesis is focusing on the application of carbon materials in the photoanode, and we have prepared the graphene(G)/Ti O2 and carbon nanotube(CNT)/Ti O2 composite photoanodes. The main contents and results are summarized as follows:1. Graphite oxide(GO) was synthesized by the modified Hummers method, then the GO was reduced to G. CNTs were dealed with strong acid to produce some carboxyl groups. The free-standing Ti O2 nanotube array film was prepared by an optimized two-step anodization. Their morphology and structure were characterized by XRD, TEM, FESEM and FT-IR.2. Conductive glass was coated by graphene layer, which was spinning coated by Ti O2 nanoparticle layer to prepare the G/Ti O2 composite photoanodes. Results indicated that the photo to current conversion efficiency was increased by 13.6%.3. For the first time, DSSCs were fabricated using Ti O2 nanotube arrays film as the photoanodes, which were adhered by a G-Ti O2 composite paste. The optimized DSSC efficiency of 6.29% was achieved at a suitable graphene concentration of 0.1 wt%, which was much improved contrast to the original efficiency of 4.35%.4. For the first time, DSSCs were fabricated using Ti O2 nanotube arrays film as the photoanodes, which were adhered by a CNT-Ti O2 composite paste. It was found that the optimized DSSC efficiency of 6.77 % was achieved at a suitable CNT concentration of 0.1 wt%.The photoanodes with new-type structure have provided a new route to enrich the structure diversification of photoanodes and improve the light-to-electric energy conversion efficiency. There are 41 figures, 8 tables and 97 references in this article.