Anisotropic Broadband Photoresponse of Layered Type‐II Weyl Semimetal MoTe2. Issue 22 (17th April 2018)

• Record Type: Journal Article
• Authors: Lai, Jiawei; Liu, Xin; Ma, Junchao; Wang, Qinsheng; Zhang, Kenan; Ren, Xiao; Liu, Yinan; Gu, Qiangqiang; Zhuo, Xiao; Lu, Wei; Wu, Yang; Li, Yuan; Feng, Ji; Zhou, Shuyun; Chen, Jian‐Hao; Sun, Dong
• Is Part Of: Advanced materials. Volume 30:Issue 22(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-04-17
• Subjects: anisotropy -- photodetectors -- Weyl semimetals; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.201707152
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Photodetectors based on Weyl semimetal promise extreme performance in terms of highly sensitive, broadband and self‐powered operation owing to its extraordinary material properties. Layered Type‐II Weyl semimetal that break Lorentz invariance can be further integrated with other two‐dimensional materials to form van der Waals heterostructures and realize multiple functionalities inheriting the advantages of other two‐dimensional materials. Herein, we report the realization of a broadband self‐powered photodetector based on Type‐II Weyl semimetal Td ‐MoTe2 . The prototype metal–MoTe2 –metal photodetector exhibits a responsivity of 0.40 mA W −1 and specific directivity of 1.07 × 10 8 Jones with 43 μs response time at 532 nm. Broadband responses from 532 nm to 10.6 μm are experimentally tested with a potential detection range extendable to far‐infrared and terahertz. Furthermore, we identify the response of the detector is polarization angle sensitive due to the anisotropic response of MoTe2 . The anisotropy is found to be wavelength dependent, and the degree of anisotropy increases as the excitation wavelength gets closer to the Weyl nodes. In addition, with power and temperature dependent photoresponse measurements, the photocurrent generation mechanisms are investigated. Our results suggest this emerging class of materials can be harnessed for broadband angle sensitive, self‐powered photodetection with decent responsivities. Abstract : A broadband self‐powered photodetector based on the layered Type‐II Weyl semimetal Td ‐MoTe2 exhibits a responsivity of 0.40 mA W ‐1 and specific directivity of 1.07 × 10 8 Jones with 43 μs response time at 532 nm. The response of the detector is polarization‐angle sensitive and the degree of anisotropic response increases as the excitation wavelength gets closer to the Weyl nodes.