POS5-0920
Additive-Assisted Morphology Engineering for High-Performance Near-Infrared Organic Photodetectors
When and Where
Nov 30, -0001
00:00 - 00:00
Presenter(s)
Jongwon Choi (KRICT)
Co-Author(s)
Abstract
Near-infrared (NIR) organic photodetectors (OPDs) have attracted significant attention due to their potential applications in biosensing, imaging, and optical communication. To achieve highly sensitive detection in the NIR region, the development of low-bandgap active materials capable of harvesting photons beyond 1000 nm is essential. Previously, our research group developed the DOTRCN, a non-fullerene acceptor (NFA) featuring a dithienopyrrole (DTP) core, (ethylhexyloxy)thiophenecarbonitrile π-bridges, and cyano-substituted indene (IC) end-group, which demonstrates specific detectivity beyond 1100 nm. However, initial bulk-heterojunction (BHJ) OPD devices based on the PTB7-Th:DOTRCN blend exhibited suboptimal NIR detection characteristics, primary due to excessive aggregation and inefficient phase separation, resulting in limited external quantum efficiency (EQE) and high dark current density.
To address these limitations, an additive engineering strategy was applied to systematically regulate the nanomorphology of PTB7-Th:DOTRCN active layers. A comprehensive investigation, covering morphological characterization, molecular packing analysis, and charge carrier dynamics, revealed that the introduction of specific additives effectively optimizes the donor–acceptor phase-separated morphology and molecular structure. Consequently, the optimized phase-separated morphology and molecular structure effectively suppresses trap-assisted recombination and facilitating efficient charge extraction, thereby significantly enhancing responsivity and specific detectivity.
These results underscore the critical role of morphology engineering in NIR OPD active materials and provide an effective optimization strategy for the development of high-performance NIR-sensitive OPDs.
To address these limitations, an additive engineering strategy was applied to systematically regulate the nanomorphology of PTB7-Th:DOTRCN active layers. A comprehensive investigation, covering morphological characterization, molecular packing analysis, and charge carrier dynamics, revealed that the introduction of specific additives effectively optimizes the donor–acceptor phase-separated morphology and molecular structure. Consequently, the optimized phase-separated morphology and molecular structure effectively suppresses trap-assisted recombination and facilitating efficient charge extraction, thereby significantly enhancing responsivity and specific detectivity.
These results underscore the critical role of morphology engineering in NIR OPD active materials and provide an effective optimization strategy for the development of high-performance NIR-sensitive OPDs.
