Sidechain engineering in poly(2,3-alkylthieno[3,4-b]pyrazine)s via GRIM polymerization: solubility, film formation, and device performance†
Abstract
The effects of branched vs. linear alkyl sidechains were investigated in poly(2,3-dialkylthieno[3,4-b]pyrazine)s via GRIM polymerization, focusing on molecular weight, processibility, and device performance. New 2-ethylhexyl derivatives exhibited enhancement in nearly all aspects, with photovoltaic devices exhibiting photoresponse out to 1300 nm and competitive specific detectivity values for NIR photodetectors.