Broadband terahertz detection and heterodyne mixing in a TaIrTe<sub>4</sub>/graphene heterojunction

Xiaokai Pan; Yichong Zhang; Xianghu Wang; Li Han; Xiaofang Wang; Lin Wang

doi:10.1088/1674-4926/26050017

J. Semicond. > Just Accepted

ARTICLES

Broadband terahertz detection and heterodyne mixing in a TaIrTe₄/graphene heterojunction

Xiaokai Pan^{1, 2, §}, Yichong Zhang^{2, §}, Xianghu Wang¹, Li Han^3,, Xiaofang Wang^1, and Lin Wang²

+ Author Affiliations

1. School of Arts and Sciences, Shanghai Dianji University, Shanghai 201306, China
2. State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
3. College of Optical and Electronic Technology, China Jiliang University, Hangzhou 310018, China
^§Xiaokai Pan and Yichong Zhang contributed equally to this work and should be considered as co-first authors.

Author Bio:

Xiaokai Pan received his bachelor’s degree from Zhejiang University of Science and Technology in 2020 and is currently a PhD. student at the Shanghai Institute of Technical Physics, Chinese Academy of Sciences, under the supervision of Researcher Lin Wang. His research focuses on terahertz detection effects in semimetal quantum structures and their applications.

Li Han received his PhD degree from Donghua University. Then he joined the Shanghai Institute of Technical Physics as a postdoctoral fellow. In July 2024, he joined China Jiliang University as a Lecturer. His research interests are centered on plasmonics and photodetection.

Xiaofang Wang had obtained her PhD degree in 2010 from the Shanghai Institute of Technical Physics, Chinese Academy of Sciences. She engaged in scientific research at the institute until 2024.In January 2025, she joined Shanghai Dianji University as a teacher and researcher. Her research interests include optoelectronic detection physics, spintronics, functional coatings and their thorough understanding of the basic physics of such devices.

Corresponding author: Li Han, hanli@cjlu.edu.cn; Xiaofang Wang, 32170@sdju.edu.cn

DOI: 10.1088/1674-4926/26050017CSTR: 32376.14.1674-4926.26050017

Abstract: Terahertz (THz) detection finds broad application in communications, imaging, astronomy, and biomedicine, imposing core requirements for broadband operation, high speed, and high sensitivity. Two-dimensional topological semimetals with superior optoelectronic properties hold significant promise for improving sensitivity, response speed, and signal-to-noise ratio. Here, a TaIrTe₄/graphene heterojunction detector based on the type-II Weyl semimetal TaIrTe₄ is constructed. Under zero external bias, the device generates a photocurrent via the photothermoelectric (PTE) effect driven jointly by an asymmetric Seebeck coefficient and a built-in temperature gradient, enabling high-performance THz detection. The device covers a broad spectral range of 0.02−0.31 THz, achieves a peak current responsivity of 1.84 A/W, a minimum noise-equivalent power (NEP) of 30 pW·Hz^–1/2, and a response time below 300 ns. It also supports heterodyne detection, sensing weak signals from a radio-frequency (RF) source with output power below –25 dBm, and exhibits a linear dynamic range exceeding 35 dB. These results underscore the importance of exploring topological semimetals for the development of broadband, high-speed, and high-sensitivity THz detectors.

Keywords: terahertz detector, topological semimetal, heterodyne detection, imaging

References

[1]	Liu K, Feng Y N, Han C, et al. High-speed 0.22 THz communication system with 84 Gbps for real-time uncompressed 8K video transmission of live events. Nat Commun, 2024, 15(1): 8037 doi: 10.1038/s41467-024-52370-x
[2]	Li X R, Li J X, Li Y H, et al. High-throughput terahertz imaging: progress and challenges. Light Sci Appl, 2023, 12(1): 233 doi: 10.1038/s41377-023-01278-0
[3]	Peng Y, Shi C J, Zhu Y M, et al. Terahertz spectroscopy in biomedical field: a review on signal-to-noise ratio improvement. PhotoniX, 2020, 1(1): 12 doi: 10.1186/s43074-020-00011-z
[4]	Peng Y, Huang J L, Luo J, et al. Three-step one-way model in terahertz biomedical detection. PhotoniX, 2021, 2(1): 12 doi: 10.1186/s43074-021-00034-0
[5]	Wang N, Cakmakyapan S, Lin Y J, et al. Room-temperature heterodyne terahertz detection with quantum-level sensitivity. Nat Astron, 2019, 3(11): 977-982 doi: 10.1038/s41550-019-0828-6
[6]	Rogalski A. Progress in performance development of room temperature direct terahertz detectors. J Infrared Millim Terahertz Waves, 2022, 43(9): 709-727
[7]	Dai M J, Zhang X R, Wang Q J. 2D materials for photothermoelectric detectors: mechanisms, materials, and devices. Adv Funct Mater, 2024, 34(21): 2312872 doi: 10.1002/adfm.202312872
[8]	Long M S, Wang P, Fang H H, et al. Progress, challenges, and opportunities for 2D material based photodetectors. Adv Funct Mater, 2019, 29(19): 1803807 doi: 10.1002/adfm.201803807
[9]	Li Y, Yu W Z, Zhang K, et al. Two-dimensional topological semimetals: an emerging candidate for terahertz detectors and on-chip integration. Mater Horiz, 2024, 11(11): 2572-2602 doi: 10.1039/D3MH02250A
[10]	Lv X Y, Zhang K X, Jiang M J, et al. Enhancement of terahertz response in a microstructure-integrated-type-II Dirac semimetal. AIP Adv, 2023, 13(11): 115223 doi: 10.1063/5.0175151
[11]	Cai M, Zhang J H, Chen Y B, et al. Giant room-temperature terahertz photothermoelectric response mediated by hot carriers at the metal-semimetal interfaces. Sci Adv, 2025, 11(20): eadv0768 doi: 10.1126/sciadv.adv0768
[12]	Hu Z, Zhang L B, Chakraborty A, et al. Terahertz nonlinear Hall rectifiers based on spin-polarized topological electronic states in 1T-CoTe₂. Adv Mater, 2023, 35(10): 2209557 doi: 10.1002/adma.202209557
[13]	Jiang H T, Xi T R, Li J X, et al. Probing interplay of topological properties and electron correlation in TaIrTe₄ via nonlinear Hall effect. Nat Commun, 2025, 16: 6351 doi: 10.1038/s41467-025-61347-3
[14]	Wang Y X, Zhang X Y, Li C H, et al. Visualization of bulk and edge photocurrent flow in anisotropic Weyl semimetals. Nat Phys, 2023, 19(4): 507-514 doi: 10.1038/s41567-022-01898-0
[15]	Xi T R, Jiang H T, Li J X, et al. Terahertz sensing based on the nonlinear electrodynamics of the two-dimensional correlated topological semimetal TaIrTe₄. Nat Electron, 2025, 8(7): 578-586 doi: 10.1038/s41928-025-01397-z
[16]	Hu Z, Zhao B J, Wei Y D, et al. High-performance terahertz detection in Weyl semimetal NbP nanosheets. Infrared Phys Technol, 2025, 149: 105896 doi: 10.1016/j.infrared.2025.105896
[17]	Tang K Q, Pan X K, Dong Z, et al. Sensitive and anisotropic room-temperature terahertz photodetection in quasi-1D nodal-line semimetal NbNiTe₅. Small, 2025, 21(12): 2410701 doi: 10.1002/smll.202410701
[18]	Yao C Y, Zhang L B, Wei Y D, et al. Broadband terahertz detector based on topological insulator heterojunction. J Infrared Millim Waves, 2023, 42(3): 362-368
[19]	Zhang K X, Hu Z, Zhang L B, et al. Ultrasensitive self-driven terahertz photodetectors based on low-energy type-II Dirac fermions and related van der Waals heterojunctions. Small, 2023, 19(1): 2205329 doi: 10.1002/smll.202205329
[20]	Pan X K, Zhang K X, Fan H C, et al. Fast and sensitive on-chip homo/heterodyne detection for terahertz communication and imaging. ACS Nano, 2026, 20(2): 2258-2268 doi: 10.1021/acsnano.5c17628
[21]	He Y, Yang L, Hu Z, et al. Selective growth of type-II Weyl-semimetal and van der Waals stacking for sensitive terahertz photodetection. Adv Funct Mater, 2024, 34(12): 2311008 doi: 10.1002/adfm.202311008
[22]	Wei Y D, Jing W C, Wu Y L, et al. Harnessing van Hove singularities for terahertz photoresponse via Fermi surface reconstruction in kagome lattices. Nat Commun, 2026, 17(1): 885 doi: 10.1038/s41467-025-66749-x
[23]	Hu Z, Pan X K, Ahammed R, et al. An all-in-one Hall rectenna with a bandwidth over 100 GHz. Nat Electron, 2026, 9(2): 140-151 doi: 10.1038/s41928-026-01574-8

Fig. 1. (Color online) (a) Schematic of the designed bow-tie antenna structure and the corresponding simulation results. (b) Optical micrograph of the device and a cross-sectional schematic; the white scale bar in the lower right corner indicates 50 μm. (c) I−V characteristics of the device. (d) Schematic illustration of the photothermoelectric mechanism in the TaIrTe₄/graphene heterojunction terahertz detector, where the arrows indicate the direction of net electron flow from the hot region to the cold region.

DownLoad: Full-Size Img PowerPoint

Fig. 2. (Color online) (a) Spectrogram of the photoresponse of the device. (b) Photocurrent as a function of source output power. (c) Responsivity versus bias voltage at 33, 93, and 275 GHz. (d) Current responsivity as a function of RF source output power under different bias voltages. (e), (f) Photoresponse waveforms at 93 and 275 GHz under different bias voltages.

DownLoad: Full-Size Img PowerPoint

Fig. 3. (Color online) (a) Experimental setup for response-time characterization. (b) Device rise/fall time. (c) Zero-bias noise current spectrum. (d) Zero-bias noise-equivalent power.

DownLoad: Full-Size Img PowerPoint

Fig. 4. (Color online) (a) Block diagram of the heterodyne detection chain. (b) Heterodyne mixing spectrum. (c) Linear dynamic range of the difference- and sum-frequency signals versus RF input power; the range of input power over which the output deviates by no more than 1 dB from the linear extrapolation is defined as the linear operating region, whose upper limit corresponds to the 1 dB compression point. (d) Intermediate-frequency output as a function of RF input power at different local-oscillator frequencies (15, 30, and 45 GHz). (e) Intermediate-frequency bandwidth of the device.

DownLoad: Full-Size Img PowerPoint

Fig. 5. (Color online) Schematic of the THz scanning imaging optical layout. The upper-left inset shows the test object, and the right inset presents the imaging results obtained at 100 and 300 GHz.

DownLoad: Full-Size Img PowerPoint

[1]	Liu K, Feng Y N, Han C, et al. High-speed 0.22 THz communication system with 84 Gbps for real-time uncompressed 8K video transmission of live events. Nat Commun, 2024, 15(1): 8037 doi: 10.1038/s41467-024-52370-x
[2]	Li X R, Li J X, Li Y H, et al. High-throughput terahertz imaging: progress and challenges. Light Sci Appl, 2023, 12(1): 233 doi: 10.1038/s41377-023-01278-0
[3]	Peng Y, Shi C J, Zhu Y M, et al. Terahertz spectroscopy in biomedical field: a review on signal-to-noise ratio improvement. PhotoniX, 2020, 1(1): 12 doi: 10.1186/s43074-020-00011-z
[4]	Peng Y, Huang J L, Luo J, et al. Three-step one-way model in terahertz biomedical detection. PhotoniX, 2021, 2(1): 12 doi: 10.1186/s43074-021-00034-0
[5]	Wang N, Cakmakyapan S, Lin Y J, et al. Room-temperature heterodyne terahertz detection with quantum-level sensitivity. Nat Astron, 2019, 3(11): 977-982 doi: 10.1038/s41550-019-0828-6
[6]	Rogalski A. Progress in performance development of room temperature direct terahertz detectors. J Infrared Millim Terahertz Waves, 2022, 43(9): 709-727
[7]	Dai M J, Zhang X R, Wang Q J. 2D materials for photothermoelectric detectors: mechanisms, materials, and devices. Adv Funct Mater, 2024, 34(21): 2312872 doi: 10.1002/adfm.202312872
[8]	Long M S, Wang P, Fang H H, et al. Progress, challenges, and opportunities for 2D material based photodetectors. Adv Funct Mater, 2019, 29(19): 1803807 doi: 10.1002/adfm.201803807
[9]	Li Y, Yu W Z, Zhang K, et al. Two-dimensional topological semimetals: an emerging candidate for terahertz detectors and on-chip integration. Mater Horiz, 2024, 11(11): 2572-2602 doi: 10.1039/D3MH02250A
[10]	Lv X Y, Zhang K X, Jiang M J, et al. Enhancement of terahertz response in a microstructure-integrated-type-II Dirac semimetal. AIP Adv, 2023, 13(11): 115223 doi: 10.1063/5.0175151
[11]	Cai M, Zhang J H, Chen Y B, et al. Giant room-temperature terahertz photothermoelectric response mediated by hot carriers at the metal-semimetal interfaces. Sci Adv, 2025, 11(20): eadv0768 doi: 10.1126/sciadv.adv0768
[12]	Hu Z, Zhang L B, Chakraborty A, et al. Terahertz nonlinear Hall rectifiers based on spin-polarized topological electronic states in 1T-CoTe₂. Adv Mater, 2023, 35(10): 2209557 doi: 10.1002/adma.202209557
[13]	Jiang H T, Xi T R, Li J X, et al. Probing interplay of topological properties and electron correlation in TaIrTe₄ via nonlinear Hall effect. Nat Commun, 2025, 16: 6351 doi: 10.1038/s41467-025-61347-3
[14]	Wang Y X, Zhang X Y, Li C H, et al. Visualization of bulk and edge photocurrent flow in anisotropic Weyl semimetals. Nat Phys, 2023, 19(4): 507-514 doi: 10.1038/s41567-022-01898-0
[15]	Xi T R, Jiang H T, Li J X, et al. Terahertz sensing based on the nonlinear electrodynamics of the two-dimensional correlated topological semimetal TaIrTe₄. Nat Electron, 2025, 8(7): 578-586 doi: 10.1038/s41928-025-01397-z
[16]	Hu Z, Zhao B J, Wei Y D, et al. High-performance terahertz detection in Weyl semimetal NbP nanosheets. Infrared Phys Technol, 2025, 149: 105896 doi: 10.1016/j.infrared.2025.105896
[17]	Tang K Q, Pan X K, Dong Z, et al. Sensitive and anisotropic room-temperature terahertz photodetection in quasi-1D nodal-line semimetal NbNiTe₅. Small, 2025, 21(12): 2410701 doi: 10.1002/smll.202410701
[18]	Yao C Y, Zhang L B, Wei Y D, et al. Broadband terahertz detector based on topological insulator heterojunction. J Infrared Millim Waves, 2023, 42(3): 362-368
[19]	Zhang K X, Hu Z, Zhang L B, et al. Ultrasensitive self-driven terahertz photodetectors based on low-energy type-II Dirac fermions and related van der Waals heterojunctions. Small, 2023, 19(1): 2205329 doi: 10.1002/smll.202205329
[20]	Pan X K, Zhang K X, Fan H C, et al. Fast and sensitive on-chip homo/heterodyne detection for terahertz communication and imaging. ACS Nano, 2026, 20(2): 2258-2268 doi: 10.1021/acsnano.5c17628
[21]	He Y, Yang L, Hu Z, et al. Selective growth of type-II Weyl-semimetal and van der Waals stacking for sensitive terahertz photodetection. Adv Funct Mater, 2024, 34(12): 2311008 doi: 10.1002/adfm.202311008
[22]	Wei Y D, Jing W C, Wu Y L, et al. Harnessing van Hove singularities for terahertz photoresponse via Fermi surface reconstruction in kagome lattices. Nat Commun, 2026, 17(1): 885 doi: 10.1038/s41467-025-66749-x
[23]	Hu Z, Pan X K, Ahammed R, et al. An all-in-one Hall rectenna with a bandwidth over 100 GHz. Nat Electron, 2026, 9(2): 140-151 doi: 10.1038/s41928-026-01574-8

Search

GET CITATION

shu

Export: BibTex EndNote

Article Metrics

Article views: 2 Times PDF downloads: 0 Times Cited by: 0 Times

History

Received: 11 May 2026 Revised: 06 July 2026 Online: Accepted Manuscript: 09 October 2026

Article Navigation > Journal of Semiconductors > 2026 > Accepted Manuscript

Xiaokai Pan, Yichong Zhang, Xianghu Wang, Li Han, Xiaofang Wang, Lin Wang. Broadband terahertz detection and heterodyne mixing in a TaIrTe4/graphene heterojunction[J]. Journal of Semiconductors, 2026, In Press. doi: 10.1088/1674-4926/26050017 ****X K Pan, Y C Zhang, X H Wang, L Han, X F Wang, and L Wang, Broadband terahertz detection and heterodyne mixing in a TaIrTe4/graphene heterojunction[J]. J. Semicond., 2026, accepted doi: 10.1088/1674-4926/26050017

Citation:

Xiaokai Pan, Yichong Zhang, Xianghu Wang, Li Han, Xiaofang Wang, Lin Wang. Broadband terahertz detection and heterodyne mixing in a TaIrTe₄/graphene heterojunction[J]. Journal of Semiconductors, 2026, In Press. doi: 10.1088/1674-4926/26050017 ****

X K Pan, Y C Zhang, X H Wang, L Han, X F Wang, and L Wang, Broadband terahertz detection and heterodyne mixing in a TaIrTe₄/graphene heterojunction[J]. J. Semicond., 2026, accepted doi: 10.1088/1674-4926/26050017

Citation:

PDF( 6357 KB)

Broadband terahertz detection and heterodyne mixing in a TaIrTe₄/graphene heterojunction

DOI: 10.1088/1674-4926/26050017

CSTR: 32376.14.1674-4926.26050017

Xiaokai Pan^{1, 2, §},
Yichong Zhang^{2, §},
Xianghu Wang¹,
Li Han^3,,
Xiaofang Wang^1,,
Lin Wang²

1.
School of Arts and Sciences, Shanghai Dianji University, Shanghai 201306, China
2.
State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
3.
College of Optical and Electronic Technology, China Jiliang University, Hangzhou 310018, China

More Information

Xiaokai Pan received his bachelor’s degree from Zhejiang University of Science and Technology in 2020 and is currently a PhD. student at the Shanghai Institute of Technical Physics, Chinese Academy of Sciences, under the supervision of Researcher Lin Wang. His research focuses on terahertz detection effects in semimetal quantum structures and their applications
Li Han received his PhD degree from Donghua University. Then he joined the Shanghai Institute of Technical Physics as a postdoctoral fellow. In July 2024, he joined China Jiliang University as a Lecturer. His research interests are centered on plasmonics and photodetection
Xiaofang Wang had obtained her PhD degree in 2010 from the Shanghai Institute of Technical Physics, Chinese Academy of Sciences. She engaged in scientific research at the institute until 2024.In January 2025, she joined Shanghai Dianji University as a teacher and researcher. Her research interests include optoelectronic detection physics, spintronics, functional coatings and their thorough understanding of the basic physics of such devices
Corresponding author: hanli@cjlu.edu.cn; 32170@sdju.edu.cn
Received Date: 2026-05-11
Revised Date: 2026-07-06

Available Online: 2026-10-09

Abstract

Abstract

Terahertz (THz) detection finds broad application in communications, imaging, astronomy, and biomedicine, imposing core requirements for broadband operation, high speed, and high sensitivity. Two-dimensional topological semimetals with superior optoelectronic properties hold significant promise for improving sensitivity, response speed, and signal-to-noise ratio. Here, a TaIrTe₄/graphene heterojunction detector based on the type-II Weyl semimetal TaIrTe₄ is constructed. Under zero external bias, the device generates a photocurrent via the photothermoelectric (PTE) effect driven jointly by an asymmetric Seebeck coefficient and a built-in temperature gradient, enabling high-performance THz detection. The device covers a broad spectral range of 0.02−0.31 THz, achieves a peak current responsivity of 1.84 A/W, a minimum noise-equivalent power (NEP) of 30 pW·Hz^–1/2, and a response time below 300 ns. It also supports heterodyne detection, sensing weak signals from a radio-frequency (RF) source with output power below –25 dBm, and exhibits a linear dynamic range exceeding 35 dB. These results underscore the importance of exploring topological semimetals for the development of broadband, high-speed, and high-sensitivity THz detectors.
- terahertz detector,
- topological semimetal,
- heterodyne detection,
- imaging

^§Xiaokai Pan and Yichong Zhang contributed equally to this work and should be considered as co-first authors.

FullText(HTML)

References(23)