POS5-1592
Side-Chain Engineering of Non-Fullerene Acceptors for Enhanced Photoresponse in SWIR Organic Photodetectors
When and Where
Nov 30, -0001
00:00 - 00:00
Presenter(s)
Kyubeen Kwak (Chungnam National University)
Co-Author(s)
Abstract
Organic photodetectors (OPDs) operating in the short-wavelength infrared (SWIR) region require non-fullerene acceptors (NFAs) with ultra-narrow bandgaps while maintaining efficient intermolecular charge transport. We report two quinoidal NFAs, based on an A-D-A'-D-A molecular framework. To investigate the effect of side-chain engineering, phenyl and thienyl substituents were introduced into the central core. Replacing the phenyl side chain with thienyl increases the quinoidal character, strengthens intramolecular charge transfer, and reduces backbone torsion, resulting in a more planar molecular structure with enhanced intermolecular interactions. Consequently, thienyl NFA exhibits slightly red-shifted absorption with an absorption onset of 1188 nm and a narrow optical bandgap of 1.08 eV. In the solid state, thienyl NFA exhibits tighter π-π stacking and improved molecular ordering while retaining a smooth film morphology. These results demonstrate that side-chain engineering of quinoidal NFAs effectively modulates both the electronic structure and molecular packing, providing a molecular design approach for extending the SWIR photoresponse of organic photodetectors.
