Study On Screening And Modulation Of Polychromatic Natural Dyes And Their Photoelectric Response Characteristics

Dye-sensitized solar cell is a new type of solar cell.Because of its simple preparation process,low production cost and other characteristics,dye-sensitized solar cell has attracted the attention of researchers at home and abroad.Sensitizers,as an important part of the dye-sensitized solar cell,play a crucial role in the photoelectric conversion efficiency of the prepared dye-sensitized solar cell.Dye-sensitized solar cell works in a similar way to photosynthesis in plants.Therefore,the effect of pigments in natural plants on plant photosynthesis is also applicable to the use of natural dyes as sensitizers for sensitized solar cells.Natural plant dyes have become a new developing direction of dye-sensitized solar cell because of their wide source,rich variety,simple extraction,low cost and little pollution to the environment.In this experiment,the dyes were extracted from the natural plants by solution extraction and ultrasonic extraction.Through the extraction and analysis of 20 kinds of plant dyes in red,yellow,green and purple.The Sun absorption effect of different kinds of plant dyes was studied.The experimental results showed that the absorption of blue-violet light at350-500 nm was better than that of red-orange light at 600-700 nm.However,purple dyes had obvious absorption peaks in the wavelength range of 680-700 nm.Through the comparison of the effective components of plant dyes,it is found that purple plant dyes containing more anthocyanins have better sensitization effect.The Dye prepared above is used as sensitizer to prepare the dye-sensitized solar cells.The relationship between the photoelectric conversion effect of various dyes and the effective components of dyes was determined by studying the effective components of dyes.The experimental results show that the photoelectric conversion efficiency of the dyes prepared by ultrasonic extraction is slightly better than that of the dyes prepared by solution extraction.The efficiency of the prepared dye-sensitive solar cells is 0.986% and 0.017%,respectively.The best photoelectric conversion efficiency of each color line is Chinese wolfberry,carrot,spinach and mangosteen peel,the conversion efficiency is 0.354%,0.203%,0.383% and0.986% respectively.In addition,purple plants had better sensitization effect than the other three color plants,while yellow plants had the worst sensitization effect.By comparing the effective components of plant dyes,it was found that the purple plant dyes had the best sensitization effect.In this paper,the sensitizing effect of mixed dyes was investigated.The sensitizing effect was observed by adding different proportion of other dyes into the purple grape peel dye which had the best sensitizing effect.The results showed that the sensitizing effect of the dyes was improved after mixing.The sensitizing effect of the mixed dyes prepared with thevolume ratio of 1:1 is the best.The best photoelectric conversion efficiency was the volume ratio of grape peel and spinach 1:1 mixed dye,with the highest photoelectric conversion efficiency of 1.096%.The effects of storage time on the absorbency and photoelectric conversion efficiency of grape dyes were studied.By comparing the properties of grape dyes stored for 0,2 and 4 days,it can be concluded that the properties of natural dyes containing anthocyanin,represented by grapes,will decrease with the increase of storage time.They should be used to do the current match,and avoid prolonged exposure.