Study On The Extracting And Co-sensitization Of Plateau Natural Dye In Dye Sensitized Solar Cells

Dye-sensitized solar cells(DSC) is a new type of solar cells. It was first invented by the Swiss scientists Michael Gratzel and Brian O,Regan in 1991 for the first time. After about 20 years,the development, its photoelectric conversion efficiency has been improved steadily from 7.1% in 1997 reported to 13%, the highest efficiency at the present literature reported. But it still failed to achieve the large-scale industrialization, one of the important reasons is that most of the sensitizers in DSC are synthetic. Synthetic dyes contain precious metal elements, the complex synthesis and separation processes, high cost and environmental pollution, which limit its widespread use. In recent years, natural dyes with the advantages of resources, simple extraction method, low cost, high molar absorption coefficient, and low environmental pollution, have become a new hotspot in the field of dye sensitizer. As the Tibetan Plateau has the particular geographical features such as high altitude, long time irradiate of ultraviolet ra and so on, it has a lot of the Qinghai-tibet plateau special plants. The research and development of plateau natural dye sensitizer in the Tibetan plateau have very prominent regional advantages. This paper is reported DSCs with dye sensitizer extracts from garden cosmos.1. This paper fabricated the DSCs using natural dyes as sensitizers, which were extracted from Tibetan Plateau plants, and the light absorption performance was measured. DSC were assembled with Garden cosmos pigment and spinach pigment, and the photoelectric performance and adsorption manner of the two kinds of dye on Ti O2 were studied.2. Garden cosmos pigment was separated with column chromatography. Each component of light and heat stability were studied. DSC were fabricated with the component of good photoelectric performance and the photoelectric properties were studied.3. The effect of co-sensitized means on light absorption performance and battery performance were studied. The effects of the best volume ratio of co-sensitization, the optimal co-sensitization time and the optimal co-sensitization concentration were discussed. It showed that the best volume ratio of co-sensitization was 1:1, the optimal co-sensitization time was 15 min, and the optimal co-sensitization concentration were separately 11.53 mg/m L and 1.18 mg/m L.4. The energy levels of four different kinds of dye solution including anthocyanin, β-carotene, their mixture and the mixture with co-adsorbent of deoxycholic acid(DCA) were studied by the electrochemical method; at the same time,the energy level matching relationship of different solutions with Ti O2 films and the electrolyte were analysed. On the basis of this, the mechanism of co-sensitization and the effects of deoxycholic acid on the photoelectric properties of natural dye sensitized solar cells were discussed.