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Defects induced persistent photoconductivity in monolayer MoS2

Chandan, Chandan and Sarkar, S and Angadi, B (2021) Defects induced persistent photoconductivity in monolayer MoS2. In: Applied Physics Letters, 118 (17).

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Official URL: https://doi.org/10.1063/5.0048505


Understanding the relaxation mechanisms of photoexcited charge carriers in two-dimensional materials is indispensable from the fundamental point of view and for future optoelectronic applications. Through the photoconductivity and electronic transport experiments, we probe the mechanisms behind the persistent photoconductivity (PPC) in monolayer molybdenum disulfide (MoS2). The temperature (T) and power-dependent photoresponse studies reveal that the relaxation of excited charge carriers is strongly affected by the random fluctuations of local potentials. The relaxation time (�) increases from � � 12 s at T�=�16.5�K to � � 1235 s at T�=�297�K, indicating PPC is a high T phenomenon in monolayer MoS2. The transport measurements demonstrate that the defect states with the density �4.43���1014�eV�1cm-2 in a low gate voltage regime, originating from the sulfur vacancies, are responsible for these fluctuations. With a rise in temperature, the defect states undergo a transition from localization to extended states at T � 100�K and thereby form the percolation network, which profoundly influences the relaxation mechanism. Our meticulous experiments and quantitative analysis provide newer insight into the origin of PPC in monolayer MoS2 © 2021 Author(s).

Item Type: Journal Article
Publication: Applied Physics Letters
Publisher: American Institute of Physics Inc.
Additional Information: The copyright for this article belongs to American Institute of Physics Inc.
Keywords: Carrier mobility; Defects; Layered semiconductors; Molybdenum compounds; Photoconductivity; Solvents; Sulfur compounds, Electronic transport; Molybdenum disulfide; Optoelectronic applications; Percolation networks; Persistent Photoconductivity; Relaxation mechanism; Transport measurements; Two-dimensional materials, Monolayers
Department/Centre: Division of Physical & Mathematical Sciences > Physics
Date Deposited: 03 Aug 2021 06:12
Last Modified: 03 Aug 2021 06:12
URI: http://eprints.iisc.ac.in/id/eprint/68930

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