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.


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...
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...
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...
Hydrothermal synthesis of TiO₂ nanostructures for photocatalitic and photovoltaic applications
Erdoğan, Nursev; Öztürk, Abdullah; Park, Jongee; Department of Metallurgical and Materials Engineering (2017)
Titanium dioxide (TiO2) nanostructures with different crystal structures and various morphologies were synthesized by hydrothermal process to utilize them in photocatalytic and photovoltaic applications. The investigations were conducted in three different sets of systematic experimental studies. The first set of experiments was based on the synthesis of TiO2 nanostructures in the presence of strong sodium hydroxide (NaOH) catalyzer. Temperature and molarity of NaOH were kept constant while hydrothermal rea...
Synthesis, photophysical and photovoltaic properties of 11- fluorodibenzo[a,c]phenazine bearing donor–acceptor type conjugated polymers
Aktaş, Ece; Toppare, Levent Kamil; Department of Chemistry (2016)
In this study, dibenzo[a,c]phenazine moiety was modified with fluorine atom to decrease the HOMO level of acceptor unit. Benzodithiophene derivative and dibenzosilole derivative were used as donor unit in the polymer backbone. In addition, 3-hexyltihophene was used as the π-bridge molecule with their donor character in polymer backbone. Also, 3,4-ethylenedioxythiophene was used to obtain new monomer to compare oxidation potential with 3-hexylthiophene based monomer. In this manner, two new conjugated monome...
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.