Affiliation: | 1. School of Materials Science and Engineering, Harbin Institute of Technology, Shen Zhen, 518055 China;2. Hubei Key Lab on Organic and Polymeric Opto-Electronic Materials, Department of Chemistry, Wuhan University, Wuhan, 430072 China These authors contributed equally to this work.;3. Hubei Key Lab on Organic and Polymeric Opto-Electronic Materials, Department of Chemistry, Wuhan University, Wuhan, 430072 China;4. Institute of Molecular Aggregation Science, Tianjin University, Tianjin, 300072 China;5. Department of Electronic and Electrical Engineering, Southern University of Science and Technology, Shen Zhen, 518055 China |
Abstract: | Photodetectors are critical components in intelligent optoelectronic systems, and photomultiplication-capable devices are essential for detecting weak optical signals. Despite significant advances, developing photomultiplication-type organic photodetectors with high gain and low noise current simultaneously remains challenging. In this work, a new conjugated polymer PDN with singlet open-shell ground state is introduced in active layers for electron capture, and the corresponding PDN-based photodetectors exhibited an enhanced photoelectric gain and decreased dark current density at a low forward bias. At 1.5 V, the PDN-based ternary photodetector has the external quantum efficiency (EQE) up to 2552.3 % and the specific detectivity of 1.4×1014 Jones at 710 nm calculated by the measured noise current, with the gain 22 times higher than that of the control group. This study provides an approach for exploiting polymers with singlet open-shell ground state to enhance the gain of organic photodetectors. |