Affiliation:
1. State Key Laboratory of Luminescent Materials and Devices Guangdong Basic Research Center of Excellence for Energy & Information Polymer Materials Institute of Polymer Optoelectronic Materials and Devices School of Materials Science and Engineering South China University of Technology Guangzhou 510640 P. R. China
2. Lumidar Technology Co., Ltd. Guangzhou 510530 P. R. China
3. School of Chemistry and Chemical Engineering Beijing Institute of Technology Beijing 100081 P. R. China
Abstract
AbstractThe performance of organic photodetectors (OPDs) sensitive to the short‐wavelength infrared (SWIR) light lags behind commercial indium gallium arsenide (InGaAs) photodetectors primarily due to the scarcity of organic semiconductors with efficient photoelectric responses exceeding 1.3 µm. Limited by the Energy‐gap law, ultralow‐bandgap organic semiconductors usually suffer from severe non‐radiative transitions, resulting in low external quantum efficiency (EQE). Herein, a difluoro‐substituted quinoid terminal group (QC‐2F) with exceptionally strong electron‐negativity is developed for constructing a new non‐fullerene acceptor (NFA), Y‐QC4F with an ultralow bandgap of 0.83 eV. This subtle structural modification significantly enhances intermolecular packing order and density, enabling an absorption onset up to 1.5 µm while suppressing non‐radiation recombination in Y‐QC4F films. SWIR OPDs based on Y‐QC4F achieve an impressive detectivity (D*) over 1011 Jones from 0.4 to 1.5 µm under 0 V bias, with a maximum of 1.68 × 1012 Jones at 1.16 µm. Furthermore, the resulting OPDs demonstrate competitive performance with commercial photodetectors for high‐quality SWIR imaging even under 1.4 µm irradiation.
Funder
National Natural Science Foundation of China
National Key Research and Development Program of China
Basic and Applied Basic Research Foundation of Guangdong Province