Benzotriazole and Quinoxaline Containing Random Copolymers for Bulk-Heterojunction Polymer Solar Cell Applications

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Bilimleri Enstitüsü, Fen Bilimleri Enstitüsü, Türkiye

Tezin Onay Tarihi: 2015

Öğrenci: Cansel Temiz

Asıl Danışman (Eş Danışmanlı Tezler İçin): ALİ ÇIRPAN

Eş Danışman: HÜSNÜ EMRAH ÜNALAN

Özet:

In this study, benzotriazole and quinoxaline derivates bearing donor acceptor type three random copolymers were synthesized to achieve broad absorption spectrum in visible region. Quinoxalines are used as strong acceptors in conjugated polymers due to the imine nitrogen in the structure. Quinoxaline containing polymers are green in their neutral states and they reveal two distinct λmax at around 400 and 700 nm. Additionally, benzotriazole and thiophene bearing polymers are red in their neutral states with λmax at around 500 nm. In this manner, quinoxaline derivates were combined with benzotriazole and π-bridge thiophene moieties. 5,8-Dibromo-2,3di(thiophen-2-yl)quinoxaline, 5,8-dibromo-2,3-diphenylquinoxaline and 10,13dibromodibenzo[a,c]phenazine acceptor units were united with 4,7-dibromo-2-(2octyldodecyl)-2H-benzo[d][1,2,3]triazole and 2,5-bis(trimethylstannyl)thiophene via Stille coupling reaction to yield alternating donor acceptor parts with randomly vi distributed several different acceptor units through polymer backbones with broad absorption in visible region. Synthesized polymers were characterized with NMR, thermogravimetric analysis, cyclic voltammetry and UV-Vis-NIR spectroscopy. Organic solar cells device production and current-voltage property measurements were conducted in a nitrogen-filled glove box system. Organic solar cell devices with the configuration of ITO/PEDOT:PSS/Polymer:PC71BM/LiF/Al were fabricated in which polymers serve as electron donors and PC71BM as the electron acceptor in the active layer. Power conversion efficiencies of Polymer: PC71BM blends were measured under standard AM 1.5 G illumination (100 mW/cm2). The organic solar cells devices employing CoP1:PC71BM films showed power conversion efficiencies up to 2.13%.