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Self-Powered, Highly Sensitive, High-Speed Photodetection Using ITO/WSe2/SnSe2 Vertical Heterojunction

Murali, Krishna and Majumdar, Kausik (2018) Self-Powered, Highly Sensitive, High-Speed Photodetection Using ITO/WSe2/SnSe2 Vertical Heterojunction. In: IEEE TRANSACTIONS ON ELECTRON DEVICES, 65 (10). pp. 4141-4148.

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Official URL: http://dx.doi.org/10.1109/TED.2018.2864250


2-D transition metal di-chalcogenides are the promising candidates for ultralow intensity photodetection. However, the performance of these photodetectors is usually limited by ambience induced rapid performance degradation and long-lived charge trapping induced slow response with a large persistent photocurrent when the light source is switched off. Here, we demonstrate an indium tin oxide (ITO)/WSe2/SnSe2-based vertical double heterojunction photoconductive device where the photoexcited hole is confined in the double barrier quantum well, whereas the photo-excited electron can be transferred to either the ITO or the SnSe2 layer in a controlled manner. The intrinsically short transit time of the photoelectrons in the vertical double heterojunction helps us to achieve high responsivity in excess of 1100 A/W and fast transient response time on the order of 10 mu s. A large built-in field in the WSe2 sandwich layer results in photodetection at zero external bias allowing a self-powered operation mode. The encapsulation from the top and bottom protects the photo-active WSe2 layer from ambience induced detrimental effects and substrate induced trapping effects helping us to achieve repeatable characteristics over many cycles.

Item Type: Journal Article
Additional Information: Copy right for this article belong to IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Keywords: 2-D layered materials; photoconductive gain; photodetector; response time; SnSe2; WSe2
Department/Centre: Division of Electrical Sciences > Electrical Communication Engineering
Date Deposited: 09 Oct 2018 15:43
Last Modified: 09 Oct 2018 15:43
URI: http://eprints.iisc.ac.in/id/eprint/60842

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