| Affiliation: | 1. Department of Optoelectronic Science and Engineering, Donghua University, Shanghai, 201620 China;2. State Key Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai, 200083 China;3. State Key Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai, 200083 China
College of Physics and Optoelectronic Engineering, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, No. 1, Sub-Lane Xiangshan, Xihu District, Hangzhou, 310024 China;4. The 50th Research Institute of China Electronics Technology Group Corporation, Shanghai, 200331 China;5. Department of Physical and Chemical Sciences, University of L'Aquila, via Vetoio, L'Aquila, AQ, 67100 Italy;6. Department of Physics, Cheng Kung University, 1 Ta-Hsueh Road, Taiwan, 70101 China;7. CNR-IOM, Area Science Park, Strada Statale 14 8. km 163.5, Trieste, I-34149 Italy |
| Abstract: | The exotic electronic properties of topological semimetals (TSs) have opened new pathways for innovative photonic and optoelectronic devices, especially in the highly pursuit terahertz (THz) band. However, in most cases Dirac fermions lay far above or below the Fermi level, thus hindering their successful exploitation for the low-energy photonics. Here, low-energy type-II Dirac fermions in kitkaite (NiTeSe) for ultrasensitive THz detection through metal-topological semimetal-metal heterostructures are exploited. Furthermore, a heterostructure combining two Dirac materials, namely, graphene and NiTeSe, is implemented for a novel photodetector exhibiting a responsivity as high as 1.22 A W?1, with a response time of 0.6 µs, a noise-equivalent power of 18 pW Hz?0.5, with outstanding stability in the ambient conditions. This work brings to fruition of Dirac fermiology in THz technology, enabling self-powered, low-power, room-temperature, and ultrafast THz detection. |
