Thiadiazoloquinoxaline and benzodithiophene bearing polymers for electrochromic and organic photovoltaic applications


Hacioglu S. O., Ataoglu E., Hizalan G., Depci T., ÇIRPAN A., Toppare L. K.

PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS, cilt.194, sa.9, ss.937-946, 2019 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 194 Sayı: 9
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1080/10426507.2019.1577847
  • Dergi Adı: PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.937-946
  • Anahtar Kelimeler: Thiadiazoloquinoxaline, benzodithiophene, low band gap polymer, organic solar cell, electrochromism, SOLAR-CELLS, CONJUGATED POLYMERS, SMALL MOLECULES, PERFORMANCE, COPOLYMERS, EFFICIENCY, DESIGN
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

Two novel thiadiazoloquinoxaline and benzodithiophene (BDT) bearing copolymers were designed and synthesized. Different BDT units (alkoxy and thiophene substituted) were used as donor materials and the effect of alkoxy and thiophene substitution on the electrochemical, spectroelectrochemical and photovoltaic properties were investigated. Both polymers exhibited low oxidation potentials at around 0.90 V and low optical band gaps at around 1.00 eV due to the insertion of electron poor thiadiazoloquinoxaline unit into the polymer backbone. Both P1 (poly-6,7-bis(3,4-bis(decyloxy)phenyl)-4-(4,8-bis(nonan-3-yloxy)benzo[1,2-b:4,5-b']dithiophen-2-yl)-[1, 2, 5]thiadiazolo[3,4-g]quinoxaline) and P2 (poly- 4-(4,8-bis(5-(nonan-3-yl)thiophen-2-yl)benzo[1,2-b:4,5-b']dithiophen-2-yl)-6,7-bis(3,4-bis(decyloxy)phenyl)-[1, 2, 5]thiadiazolo[3,4-g]quinoxaline) exhibited multichromic behavior with different tones of greenish yellow and gray in the neutral and fully oxidized states, respectively. In addition, both polymers revealed very high optical contrasts (similar to 87%) in the NIR region which make these promising polymers good candidates for NIR applications. Finally, in order to explore the organic photovoltaic performances, P1 and P2 were mixed with PC71BM in the active layer of organic solar cells (OSCs) by conventional device structure. As a result P1 and P2 based devices revealed power conversion efficiencies (PCEs) of 0.33% and 0.60% respectively. However, the additive treatment enhanced PCE from 0.49 to 0.73% for P2 based devices.