Syntheses of benzodithiophene and thienopyrroledione containing conjugated random polymers as components for organic solar cells

Azeri, Özge
In recent years organic solar cells (OSC) have attracted considerable attention as promising candidates for renewable energy technology because of their low cost, light weight and flexibility. In this study, in order to improve the efficiency of a bulk heterojunction solar cell, two conjugated random polymers were designed. For this purpose, benzodithiophene and thienopyrroledione containing two random copolymers were synthesized. The effects of several acceptors such as benzotriazole and benzothiadiazole on optoelectronic properties and the performance of bulk heterojunction polymer solar cells were investigated. Electrochemical and optical studies prove that these polymers could be candidates for organic solar cell applications. Both copolymers were n-and p- dopable. Thus, the HOMO and LUMO values were determined by using cyclic voltammetry resulted with the values -5.53 and -3.43 eV for P1 and -5.54 and -3.53 for P2, respectively. The optical band gap of the polymers were calculated by using UV-VIS-NIR spectroscopy as 2.10 and 2.01 eV for P1 and P2, correspondingly. Bulk-heterojunction solar cells were constructed with the configuration of ITO/PEDOT:PSS/Polymer:PC71BM/LiF/Al and the synthesized polymers were used as the electron donors and PC71BM as the electron acceptor in the active layer. The best performance is observed for device of P2 1:2 (w:w) ratio with a PCE of 5.83 % under standard AM 1.5 G at 100 mW/cm2.  


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Citation Formats
Ö. Azeri, “Syntheses of benzodithiophene and thienopyrroledione containing conjugated random polymers as components for organic solar cells,” M.S. - Master of Science, Middle East Technical University, 2017.