Preparation And Characterization Of The Organic Solar Cell Materials

Since the solar energy is considered to be one representative of the clean and renewableenergy. Because of some merits, such as simple preparation, low cost, light weight and can bemade of flexible device, the solar cells which based on fullerene’s and thiophene polymer’s bulk-heterojunction has been received extensive attention in recent years. Photovoltaic conversioninnovate and improve constantly, it has become solar cells’ mainly development direction. Inorder to overcome the poor stability of solar cell and short life, this paper designs andsynthesizes some active materials of the organic solar cells.Firstly, Thiophene-fullerene system compounds with a structure of D-A are prepared. Twoderivatives of methano[60]fullerene derivatives based on Cyclopenta[c] thiophene were preparedby esterification reaction of5,5-Bis（hydroxymethyl）cyclopenta[c]thiophene and ethyl malonylchloride, and then obtained intermediate pursued a Bingel reaction with C₆₀, we got twodifferent kinds of D-A system of C₆₀-thiophene of2-1and2-2. The structures of the2-1and2-2have been characterized by IR,1H-NMR,13C-NMR, and their optoelectronic properties havebeen analysisd by UV-VIS absorption spectra and CV, finally the photovoltaic property ofcompound2-1was investigated. The consequence indicates that the compound displayphotoelectric effect. Because of poor solubility, the polymerization is difficult. So thinking aboutpractical application in the days to come, we design to change the substituent group length andthen hope to change the solubility of the substances.Secondly, in order to lengthen the length of alkyl chain and increase the solubility of targetcompound, this design changes ethyl to Methoxybenzene in structure2-1. The malonic acidmono phenol ester was synthesized by Meldrum’s acid and p-methoxyphenol, then reacted witht-butanol，asymmetric malonic acid di-ester was prepared, finally a fullerene derivative3-1wassynthesized by Bingel reaction. Then the characterization and photoelectric have been analysised.the photoelectric properties of the compound3-1will be investigated as an acceptor in bulkheterojunction （BHJ） solar cells on the basis the P3HT as a donor; In ordering to observe thedifferent substituent group influence on solubility of the compound and optoelectronic properties,and The length and property of substituent was changed. We chose the long carbon chain’stwelve alcohol reacts with Meldrum’s acid and then got malonic acid mono twelve alcoholester， which further complete the esterification with5,5-Bis（hydroxymethyl）cyclopenta[c]thiophene and Bingel reaction with C₆₀, then get two newC₆₀-Thiophene’s binary systems4-1and4-2, and then analyzed the characterization andphotoelectric separately. Both of the compounds are soluble in common organic solvents. They will be polymerized further and then generate D-A active material which Contains fullerene(C₆₀)at the polythiophene chain.Finally, C₆₀-indene derivatives: ICMA and ICBA are prepared. According to the resultsreported, its photoelectric conversion efficiency got to6.48%by utilizing the P3HT/ICBA as theactive layer of organic solar cells, but in the preparation of ICBA, a large number of toluene hasbeen used, which increases the preparation costs and the difficulty of separation and purification.At the experiments, we explore and improve the way of preparation, and simplify the conditionof extraction and separation, which led to save time of column separation. The products havehigh purity and yield and have applied for patent.