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Enhanced photoresponse in MoTe2 photodetectors with asymmetric graphene contacts

Wei, Xia; Yan, Faguang; Lv, Quanshan; Zhu, Wenkai; Hu, Ce; Patane, Amalia; Wang, Kaiyou


Xia Wei

Faguang Yan

Quanshan Lv

Wenkai Zhu

Ce Hu

Kaiyou Wang


Atomically thin two dimensional (2D) materials are promising candidates for miniaturized high-performance optoelectronic devices. Here, we report on multilayer MoTe2 photodetectors contacted with asymmetric electrodes based on n- and p-type graphene layers. The asymmetry in the graphene contacts creates a large (Ebi ~100 kV cm-1) built-in electric field across the short (l = 15 nm) MoTe2 channel, causing a high and broad (λ = 400 to 1400 nm) photoresponse even without any externally applied voltage. Spatially resolved photovoltage maps reveal an enhanced photoresponse and larger built-in electric field in regions of the MoTe2 layer between the two graphene contacts. Furthermore, a fast (~10 μs) photoresponse is achieved in both the photovoltaic and photoconductive operation modes of the junction. Our findings could be extended to other 2D materials and offer prospects for the implementation of asymmetric graphene contacts in future low-power optoelectronic applications.


Wei, X., Yan, F., Lv, Q., Zhu, W., Hu, C., Patane, A., & Wang, K. (2019). Enhanced photoresponse in MoTe2 photodetectors with asymmetric graphene contacts. Advanced Optical Materials, 7(12), Article 1900190.

Journal Article Type Article
Acceptance Date Mar 18, 2019
Online Publication Date Apr 16, 2019
Publication Date Jun 18, 2019
Deposit Date Mar 19, 2019
Publicly Available Date Apr 17, 2020
Journal Advanced Optical Materials
Electronic ISSN 2195-1071
Publisher Wiley
Peer Reviewed Peer Reviewed
Volume 7
Issue 12
Article Number 1900190
Keywords Asymmetric graphene contacts; MoTe2; van der Waals heterostructure; Built-in electric filed; Enhanced photoresponse
Public URL
Publisher URL
Additional Information This is the peer reviewed version of the following article: Wei, X., Yan, F., Lv, Q., Zhu, W., Hu, C., Patanè, A., Wang, K., Enhanced Photoresponse in MoTe2 Photodetectors with Asymmetric Graphene Contacts. Advanced Optical Materials 2019, 1900190. , which has been published in final form at . This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.


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