JOURNAL OF APPLIED POLYMER SCIENCE, cilt.142, sa.41, 2025 (SCI-Expanded, Scopus)
In this study, the influence of silicon incorporation into donor moieties of donor-acceptor (D-A) type conjugated polymers with selenophene pi-bridges for organic solar cell (OSC) applications was investigated. Two novel polymers, P1 and P2, were synthesized, with 4,4-dioctyl-4H-silolo[3,2-b:4,5-b'] dithiophene (P1) and 2,2 '-bithiophene (P2) used as donor units, while 2,1,3-benzooxadiazole (BOz) was employed as the electron-accepting unit. Optical and electrochemical analyses were conducted, revealing that the silole donor unit in P1 resulted in enhanced pi-conjugation, a lower HOMO-LUMO bandgap (1.56 eV vs. 1.64 eV for P2), and improved intermolecular charge transport properties. Superior performance was demonstrated by P1-based devices, with a PCE of 3.64%, a JSC of 8.60 mA/cm2, a VOC of 0.66 V, and a FF of 64.04%. Improved molecular planarity and pi-pi stacking in P1, attributed to the silicon-containing donor, were found to contribute to enhanced charge carrier mobility and reduced structural disorder in the active layer. The inclusion of selenophene as a pi-bridge was also observed to improve intermolecular interactions and optical absorption. It is concluded that silicon incorporation plays a crucial role in tuning the optoelectronic and photovoltaic properties of conjugated polymers, underscoring its potential for advancing the design of next-generation OSC materials and devices for renewable energy applications.