A comprehensive study: Theoretical and experimental investigation of heteroatom and substituent effects on frontier orbitals and polymer solar cell performances

Cevher Ş. C., Hizalan G., Alemdar Yilmaz E., Cevher D., Udum Arslan Y., Toppare L., ...More

JOURNAL OF POLYMER SCIENCE, vol.58, no.19, pp.2792-2806, 2020 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 58 Issue: 19
  • Publication Date: 2020
  • Doi Number: 10.1002/pol.20200513
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2792-2806
  • Keywords: benzochalcogendiazole, frontier orbital engineering, polymer solar cells, substituent effect, theoretical chemistry, OPEN-CIRCUIT VOLTAGE, CONJUGATED POLYMERS, PHOTOVOLTAIC MATERIALS, DONOR, BENZOTHIADIAZOLE, COPOLYMERS, EFFICIENCY, BENZOTRIAZOLE, BANDGAP, DESIGN
  • Middle East Technical University Affiliated: Yes


Benzochalcogendiazole derivatives are incorporated with thieno[3,4-c]pyrrole-4,6-dione (TPD) acceptor and 4,8-diethoxybenzo[1,2-b:4,5-b ']dithiophene donor to synthesize tree-component random copolymers. Four different copolymers are synthesized and their electronic, optical and photovoltaic properties are compared. Comparisons are aligned in the course of two different strategies, which are the replacement of benzochalcogendiazole moiety and the modification of side group on benzothiadiazole. Theoretical calculations by comparing the HOMO-LUMO levels, band gaps and other electronic descriptors of pristine and 2 + 2 two acceptor-based copolymers are investigated. Random copolymer bearing benzoxadiazole moiety, PO exhibits the highest photovoltaic performance of 8.29% with aJ(sc)of 14.96 mA cm(-2),V(oc)of 0.87 V, fill factor (FF) of 63.70%. PF possesses the highestV(oc)with a value of 0.88 V,J(sc)of 14.40 mA cm(-2), power conversion efficiency (PCE) of 7.32% with 58% FF. PS exhibits average feature withJ(sc)11.82 mA cm(-2),V(oc)0.80 V, FF 50%, and 4.72% PCE. Lowest performing selenadiazole containing random copolymer (PSe) copolymer exhibits maximum PCE as 3.65%. These results demonstrate the promising effectiveness of benzoxadiazole selection as an alternative acceptor unit and F atom substitution for the design of (A1-D)-(A2-D) type random copolymers for organic solar cells.