A triazoloquinoxaline and benzodithiophene bearing low band gap copolymer for electrochromic and organic photovoltaic applications


HACIOGLU S. O., UNLU N. A., AKTAS E., HIZALAN G., Yildiz E. D., ÇIRPAN A., ...Daha Fazla

SYNTHETIC METALS, cilt.228, ss.111-119, 2017 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 228
  • Basım Tarihi: 2017
  • Doi Numarası: 10.1016/j.synthmet.2017.04.017
  • Dergi Adı: SYNTHETIC METALS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.111-119
  • Anahtar Kelimeler: Conjugated polymers, Triazoloquinoxaline, Benzodithiophene, Organic solar cell, Copolymer, HETEROJUNCTION SOLAR-CELLS, CONJUGATED POLYMERS, BENZOTRIAZOLE, EFFICIENCY, ACCEPTOR, FLUORENE, DESIGN, DONOR
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

A new triazoloquinoxaline and benzodithiophene based copolymer was synthesized to investigate its electro-chemical, optical and photovoltaic behaviors. According to the polymer design, combination of two acceptor units (benzotriazole and quinoxaline) which contribute imine bonds to the structure and a triazoloquinoxaline unit for enhancing electron accepting ability was pursued. As a result of electrochemical studies, the copolymer PTQBDT has a low lying HOMO energy level as - 5.23 eV which increases the chemical stability of the resulting polymer and leads to a higher V-oc. In addition, the copolymer has an ambipolar character with two well-defined redox couples in the n-doped state and multichromic behavior. In the context of optical studies, PTQBDT has wide absorption range in the visible region with a tail in the NIR region, which yields a low band gap of 1.20 eV. Organic photovoltaic devices were designed using PTQBDT (the electron donor) and PC71BM (the electron acceptor) for the preliminary studies. The resulting device exhibits a power conversion efficiency of 2.0% with a current density of 8.07 mA cm(-2), an open-circuit voltage of 0.45 V, and a fill factor of 55%. The carrier mobility of the PTQBDT was calculated as 3.00 x 10(-3) cm(2) V-1 S-1 via space-charge-limited current (SCLC) method.