Benzodithiophene and benzotriazole bearing alternating copolymers, effect of thiophene and bithiophene _-bridges on photovoltaic properties

İstanbulluoğlu, Çağla
In this study, two novel 1,2,3-benzotriazole and benzodithiophene bearing alternating copolymers were synthesized via Stille coupling reaction. Benzodithiophene was used as the donor moiety due to its strong electron donating ability and planar structure. Benzotriazole moiety was incorporated as the acceptor unit due to its electron deficient nature. Moreover, thiophene (P1) and bithiophene (P2) conjugated moieties were incorporated between donor and acceptor units in order to investigate the effect of π-bridge. Electrochemical, spectroelectrochemical and kinetic studies were performed. Since both polymers revealed ambipolar character, HOMO-LUMO energy levels were calculated from cyclic voltammograms. As a result of kinetic studies, good stabilities and low switching times were recorded. Moreover, bithiophene bearing copolymer showed enhanced percent transmittance and low switching time at NIR region when compared with thiophene bearing polymer. Organic photovoltaic applications of the polymers were conducted with a device structure of ITO/PEDOT:PSS/POLYMER:PC70BM/LiF/Al The analysis of the photovoltaic devices was performed under standard AM 1.5G illumination. Alkyl chains on the donor and acceptor moieties enhanced the solubility of the polymers in organic solvents. Thickness and morphology of the devices were examined via AFM and TEM studies. As a result of several optimization studies, power conversion efficiencies were reached to 2.12 % and 1.20 % for P1 and P2, respectively. P1 was used as active layer for OLED applications which were constructed with a device structure of ITO/PEDOT:PSS/P1/LiF/Al. Red emissive OLED was produced with CIE coordinates (x,y) of 0.65, 0.34, respectively.


Inverted organic solar cell applications of benzodithiophene and benzotriazole bearing alternating copolymers
Bolayır, Eda; Toppare, Levent Kamil; Department of Chemistry (2018)
In this thesis, electrochemical, optical and photovoltaic studies of two novel benzodithiophene and 1,2,3-benzotriazole bearing alternating copolymers were investigated. Benzodithiophene which has a strong electron donating ability and planar structure was used as the donor moiety. On the other hand, benzotriazole was used as an acceptor moiety due to its electron deficient nature. In order to determine the effect of л-bridges, thiophene (P1) and selenophene (P2) moieties were incorporated between the donor...
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Erer, Mert Can; Çırpan, Ali; Department of Chemistry (2019)
In this study two novel random polymers, comprising benzothiadiazole and benzotriazole as the accepting units and benzodithiophene as the donor unit, were examined in terms of their photovoltaic performance. Moreover, effects thiophene and selenophene π bridges on optical, electrochemical and optoelectronic properties of the polymers were investigated. Optical band gap values of selenophene bearing P1 and thiophene P2 were found as 1.63 eV and 1.73 eV, respectively. Characterization of polymers via UV-Vis-N...
Benzotriazole and quinoxaline containing random copolymers for bulk-heterojunction polymer solar cell applications
Temiz, Cansel; Çırpan, Ali; Ünalan, Hüsnü Emrah; Department of Polymer Science and Technology (2015)
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 λ...
Syntheses and investigation of optoelectronic properties of benzothiadiazole and benzotriazole containing conjugated polymers
Keleş, Duygu; Çırpan, Ali; Arslan Udum, Yasemin; Department of Polymer Science and Technology (2017)
Benzothiadiazole is one of the most widely used acceptor units in Donor–Acceptor copolymers for organic solar cells (OSCs) with its strong electron withdrawing ability. It is also known that fluorine atom substitution directly to the backbone of conjugated polymers can improve the important parameters such as power conversion efficiency (PCE), open-circuit voltage (Voc), short-circuit current density (Jsc), and fill factor (FF) of OSCs. Besides benzothiadiazole, benzotriazole is another acceptor moiety whic...
Alkyl end group Modification of Benzotriazole and Thiophene Containing Conjugated Polymers
Cevher, Şevki Can; Keleş, Duygu; Özdemir Hacıoğlu, Şerife; Toppare, Levent Kamil; Çırpan, Ali (null; 2016-07-21)
This study focused on modifying the alkyl‐end‐group of benzotriazole and thiophene containing conjugated polymers. Introducing a moiety with struc‐turally rigid and tendency to enhance the π‐π stacking and also absorption in the high energetic region, influence the both electronic and optic properties of the conjugated polymers. Stille cross coupling chemical polymerization method was performed to synthesize the polymer contains: benzotriazole and bisthiophene. Characterizations of polymers were done in ter...
Citation Formats
Ç. İstanbulluoğlu, “Benzodithiophene and benzotriazole bearing alternating copolymers, effect of thiophene and bithiophene _-bridges on photovoltaic properties,” M.S. - Master of Science, Middle East Technical University, 2016.