Visible-blind ultraviolet narrowband photomultiplication-type organic photodetector with an ultrahigh external quantum efficiency of over 1 000 000%
| Autor: | Liqing Yang, Dezhi Yang, Jingcheng Zhao, Linge Wang, Dechao Guo, Guo He, Dongge Ma, Ji Li, Agafonov Vadim |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
business.industry Process Chemistry and Technology Photodetector 02 engineering and technology Specific detectivity 010402 general chemistry 021001 nanoscience & nanotechnology medicine.disease_cause 01 natural sciences Acceptor 0104 chemical sciences Organic semiconductor Mechanics of Materials medicine OLED Optoelectronics General Materials Science Quantum efficiency Electrical and Electronic Engineering 0210 nano-technology business Ultraviolet Visible spectrum |
| Zdroj: | Materials Horizons. 8:2293-2302 |
| ISSN: | 2051-6355 2051-6347 |
| Popis: | A visible-blind ultraviolet (UV) photodetector can detect UV signals and is not interfered with by visible light or infrared light in the environment. In order to realize high-performance visible-blind UV organic photodetectors (OPDs), we design photomultiplication-type (PM-type) OPDs by using a novel strategy. Firstly, wide bandgap organic semiconductor materials, which do not absorb visible light, are selected as donors to absorb UV light. Secondly, a very small amount of C60 is used as an acceptor to trap photogenerated electrons. These accumulating electrons near the Al electrode form a potential, which leads to band bending and narrowing of the interface barrier, thereby assisting hole-tunneling injection to form a multiplication. The fabricated visible-blind UV PM-type OPDs with donor/acceptor doping ratio of 50 : 1 exhibit a narrowband response with full-width at half-maximum (FWHM) of approximately 36 nm, an ultrahigh external quantum efficiency of 1.08 × 106% and a remarkable specific detectivity of 1.28 × 1014 jones at 335 nm wavelength under −14 V bias. The UV-to-visible rejection ratio exceeds 103 by adjusting the donor/acceptor mixing ratios. The devices made with other wide bandgap organic materials also showed similar performance, indicating that this device structure provides an effective method for the preparation of high-performance visible-blind UV PM-type OPDs. In addition, we prepared a flexible visible-blind UV PM-type OPD based on a PET substrate and integrated it with a flexible OLED to fabricate a wearable UV monitor, which can visually detect the intensity of UV light. |
| Databáze: | OpenAIRE |
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