Gain-type photodetector with GFET-coupled MoS2/WSe2 heterojunction
Due to its exceptional photovoltaic properties and freedom from crystal lattice matching constraints, transition-metal dichalcogenides (TMDCs) have gained increased attention as a prospective two-dimensional (2D) layered material. Van der Waals heterojunctions (vdWHs) constituted of these materials...
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Veröffentlicht in: | Journal of alloys and compounds 2024-10, Vol.1002, p.175475, Article 175475 |
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Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | Due to its exceptional photovoltaic properties and freedom from crystal lattice matching constraints, transition-metal dichalcogenides (TMDCs) have gained increased attention as a prospective two-dimensional (2D) layered material. Van der Waals heterojunctions (vdWHs) constituted of these materials afford chances for the advancement of high-performance photodetectors and solar cells. However, low light absorption efficiency and electron/hole traps at heterointerfaces make it difficult to improve the response speed and sensitivity of TMDCs vdWH based photodetectors. Here, we designed and realized a GFET-coupled MoS2/WSe2 heterojunction gain photodetector. An interfacial amplification effect is induced when a graphene field-effect transistor (GFET) is coupled to a MoS2/WSe2 heterojunction because of the lengthy carrier lifetime of MoS2 and the ultrahigh mobility of graphene. This effect leads to a high gain for our device, enhancing the photovoltaic response. Compared to the pristine MoS2/WSe2 heterojunction, the device exhibits two to three orders of magnitude improvement in responsivity, up to 50 A/W. Rising and decaying times of 67 μs and 2 μs are also achieved, respectively. By utilizing the strong correlation between the incident light spot position and the photocurrent, the device also enables sensitive detection of the spot position. This research offers an attainable method for developing gain-type, high-speed photodetectors.
•Coupling of GFET to 2D heterojunction improves the photoresponsivity.•Interfacial amplification effect brings high gain to photodetector.•Achieving sensitive position detection of light point by measuring photocurrent. |
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ISSN: | 0925-8388 |
DOI: | 10.1016/j.jallcom.2024.175475 |