PtTe2‐Based Type‐II Dirac Semimetal and Its van der Waals Heterostructure for Sensitive Room Temperature Terahertz Photodetection. Issue 52 (18th November 2019)

• Record Type: Journal Article
• Authors: Xu, Huang; Guo, Cheng; Zhang, Jiazhen; Guo, Wanlong; Kuo, Chia‐Nung; Lue, Chin Shan; Hu, Weida; Wang, Lin; Chen, Gang; Politano, Antonio; Chen, Xiaoshuang; Lu, Wei
• Is Part Of: Small. Volume 15:Issue 52(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-11-18
• Subjects: terahertz detection -- topological semimetals -- transition metal dichalcogenides -- van der Waals (vdW) heterostructures; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201903362
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Recent years have witnessed rapid progresses made in the photoelectric performance of two‐dimensional materials represented by graphene, black phosphorus, and transition metal dichalcogenides. Despite significant efforts, a photodetection technique capable for longer wavelength, higher working temperature as well as fast responsivity, is still facing huge challenges due to a lack of best among bandgap, dark current, and absorption ability. Exploring topological materials with nontrivial band transport leads to peculiar properties of quantized phenomena such as chiral anomaly, and magnetic‐optical effect, which enables a novel feasibility for an advanced optoelectronic device working at longer wavelength. In this work, the direct generation of photocurrent at low energy terahertz (THz) band at room temperature is implemented in a planar metal–PtTe2 –metal structure. The results show that the THz photodetector based on PtTe2 with bow‐tie‐type planar contacts possesses a high photoresponsivity (1.6 A W −1 without bias voltage) with a response time less than 20 µs, while the PtTe2 –graphene heterostructure‐based detector can reach responsivity above 1.4 kV W −1 and a response time shorter than 9 µs. Remarkably, it is already exploitable for large area imaging applications. These results suggest that topological semimetals such as PtTe2 can be ideal materials for implementation in a high‐performing photodetection system at THz band. Abstract : As a new quantum phase of matter, type‐II Dirac semimetal of PtTe2 is demonstrated acting as a highly sensitive terahertz (THz) detector. The self‐powered mode responsivity of 1.6 A W −1 is demonstrated as the intrinsic mechanism, with realistic exploration for THz imaging. It opens up a strategy for a THz detector based on type‐II Dirac semimetal and its heterostructure.