How do we get across? Impact of bridging aromatic units on the optical, electronic, and photovoltaic properties of donor-acceptor polymers

2024-01-01
Dikbıyık, Dilan Ece
Karakurt, Oğuzhan
Cevher, Duygu
Ozsoy, Gonul Hizalan
Yıldırım, Erol
Cirpan, Ali
A series of donor - π - acceptor (D- π -A) type polymers (P1, P2, and P3) containing benzodithiophene (BDT) as donor unit and benzothiadiazole (BT) as acceptor unit were designed and synthesized by incorporating diverse electron-rich π bridges as thiophene (T), selenophene (Se) and thieno[3,2-b] thiophene (TT) via Pd-catalyzed Stille cross-coupling reaction. The effect of the various -bridges on the optical and electrochemical properties of P1, P2, and P3 was examined, and for P1 and P2, the effect of π-bridges on photovoltaic properties was examined. Density functional theory (DFT) calculations were performed on tetramer model structures to understand the effect of π-bridges on the structural, electronic, and optical properties of the resulting polymers. Insertion of different π-bridges results in polymers with up-shifted highest occupied molecular orbital (HOMO). Thiophene π-bridged polymer P1:PC71BM showed the best photovoltaic performance with a power conversion efficiency (PCE) of 3.48 %, a short-circuit density (JSC) of 9.19 mA/cm2, an open-circuit voltage (VOC) of 0.75 V, and a fill factor (FF) of 50.30 %. The highest PCE obtained from a P2:PC71BM-based photovoltaic device was 2.42 %.
Citation Formats
D. E. Dikbıyık, O. Karakurt, D. Cevher, G. H. Ozsoy, E. Yıldırım, and A. Cirpan, “How do we get across? Impact of bridging aromatic units on the optical, electronic, and photovoltaic properties of donor-acceptor polymers,” POLYMER, vol. 294, pp. 1–11, 2024, Accessed: 00, 2024. [Online]. Available: https://hdl.handle.net/11511/108060.