Synthesis Optimization And Application Of Tetrabromo Anhydride

Organic solar cells have attracted great attentions because of their cheap production cost, easy fabrication and large-scale manufacture potential. The organic semiconductor material is an active ingredient of preparing a solar cell. Naphthalene diimides are excellent organic semiconductors. We discovered that it also has good performance in solar cells recently. Tetrabromo anhydride is the precursor to synthesize naphthalene diimides, so the synthesis method of tetrabromo anhydride for the development of solar cells has important significance.This paper discussed the synthesis of tetrabromo anhydride. We optimized this method by changing the reaction time, temperature, ratio of reactants and other factors, to find a high yield, short reaction time, simple operation synthesis. According to the requirements of preparation of solution processing, two D-A-D small molecular organic solar cell materials were synthesized using tetrabromo anhydride, and the physical and chemical properties and device performance were investigated. The main contents are outlined as follows:1. Using the bromine and1,3-dibromo-5,5-two methyl hydantoin (DBH) as the brominating agent, tetrabromo anhydride was synthesized at the same reaction temperature (120℃,80℃during the day and night), the same solvent (20%Oleum) and the same reaction time (21days) to make a comparative experiment. We characterized the tetrabromo anhydride by elemental analysis. The results showed that the bromide ability of DBH is stronger than bromine, and the purity of tetrabromo anhydride are higher. We carried out comparative experiments by changing the reaction time, reaction solvent, reactant ratio conditions, and determined the optimum reaction conditions:Naphthalene anhydride (NDA) and DBH ratio is1:4, reaction time is48h, reaction solvent is98%concentrated sulfuric acid.2. With naphthalene diimides as the core, we synthesized D-A-D type compounds NDI-DTYT2and NDI-DTYTT2. From the UV absorption spectra, NDI-DTYT2and NDI-DTYTT2have a broad absorption band in the700-850nm range of long wavelength direction, which is the typical characteristic of solar materials. From the electrochemical test, we observed that NDI-DTYT2and NDI-DTYTT2not only can accept electrons but also can give the electronic, indicating bipolar molecular materials. The OFET device of NDI-DTYT2and NDI-DTYTT2by solution spin coating were prepared with the electron mobility0.0036cm2V-1s-1of NDI-DTYT2and0.0023cm2V-1s-1of NDI-DTYTT2and the hole mobility0.015cm2V-1s-1of NDI-DTYT2and0.0057cm2V-1s-1of NDI-DTYTT2at120℃annealing. NDI-DTYT2and NDI-DTYTT2showed the hole and electron transport bipolar transmission behavior.