TY - JOUR

T1 - Vertically Aligned Carbon Nanotubes as a Broadband Absorber of Terahertz Radiation in Conventional and Inverted Bolometers

AU - Dem’yanenko, Michael

AU - Sheglov, Dmitry

AU - Rogilo, Dmitry

AU - Semenova, Olga

AU - Rodyakin, Sergey

AU - Yaroshevich, Alexander

AU - Ponomarev, Sergei

AU - Nasimov, Dmitriy

AU - Fedina, Liudmila

AU - Latyshev, Alexander

AU - Kuznetsov, Sergei

AU - Nikolaev, Nazar

N1 - Dem’yanenko, M., Sheglov, D., Rogilo, D. et al. Vertically Aligned Carbon Nanotubes as a Broadband Absorber of Terahertz Radiation in Conventional and Inverted Bolometers. J Infrared Milli Terahz Waves 47, 69 (2026). https://doi.org/10.1007/s10762-026-01176-7 Investigations were financially supported by Russian Science Foundation (grant number 23-72-30003). Theoretical calculations were funded by State Assignments from the Ministry of Science and Higher Education of the Russian Federation to the Rzhanov Institute of Semiconductor Physics (project no. FWGW-2025-0014).

PY - 2026/9/17

Y1 - 2026/9/17

N2 - Integrating a broadband absorber based on vertically aligned carbon nanotubes (VACNTs) with the temperature-sensitive membrane of a conventional uncooled bolometer during detector fabrication is challenging due to the high synthesis temperatures (> 600°C) and the mechanical fragility of the VACNT arrays. This paper discusses an alternative design for a broadband terahertz (THz) detector based on an inverted bolometer. This design eliminates the aforementioned problems, as the radiation absorber is implemented in the form of a thin metal layer deposited on the bolometer membrane, and an additional VACNT-based absorber is mounted on the base of the vacuum detector housing. A study of the optical properties of VACNTs grown on Si/Al₂O₃/Fe substrates in the 15–1400 μm wavelength range showed that the absorption of terahertz radiation at wavelengths longer than 100 μm is mainly due to the lateral conductivity of the VACNT arrays, which in the studied VACNT layers was approximately 0.3 S/cm. Based on the data obtained regarding the VACNT optical properties, a comparative analysis of the absorption coefficients of infrared and THz radiation in conventional and inverted bolometers was carried out. It was found that conventional bolometers with a VACNT absorbing layer thickness of less than 50 μm exhibit the best sensitivity at wavelengths shorter than 100 μm, while inverted bolometers exhibit the best sensitivity at wavelengths longer than 100 μm. The optimal lateral conductivity of VACNT layers for maximum absorption in conventional bolometers is ≈3 S/cm.

AB - Integrating a broadband absorber based on vertically aligned carbon nanotubes (VACNTs) with the temperature-sensitive membrane of a conventional uncooled bolometer during detector fabrication is challenging due to the high synthesis temperatures (> 600°C) and the mechanical fragility of the VACNT arrays. This paper discusses an alternative design for a broadband terahertz (THz) detector based on an inverted bolometer. This design eliminates the aforementioned problems, as the radiation absorber is implemented in the form of a thin metal layer deposited on the bolometer membrane, and an additional VACNT-based absorber is mounted on the base of the vacuum detector housing. A study of the optical properties of VACNTs grown on Si/Al₂O₃/Fe substrates in the 15–1400 μm wavelength range showed that the absorption of terahertz radiation at wavelengths longer than 100 μm is mainly due to the lateral conductivity of the VACNT arrays, which in the studied VACNT layers was approximately 0.3 S/cm. Based on the data obtained regarding the VACNT optical properties, a comparative analysis of the absorption coefficients of infrared and THz radiation in conventional and inverted bolometers was carried out. It was found that conventional bolometers with a VACNT absorbing layer thickness of less than 50 μm exhibit the best sensitivity at wavelengths shorter than 100 μm, while inverted bolometers exhibit the best sensitivity at wavelengths longer than 100 μm. The optimal lateral conductivity of VACNT layers for maximum absorption in conventional bolometers is ≈3 S/cm.

KW - Bolometer design

KW - Broadband absorber

KW - Terahertz radiation for sensing applications

KW - Vertically aligned carbon nanotube array

KW - Массив вертикально ориентированных углеродных нанотрубок

KW - Широкополосный поглотитель

KW - Терагерцовое излучение для сенсорных приложений

KW - Конструкция болометра

UR - https://www.mendeley.com/catalogue/6d591a09-5363-3066-9205-9960f5a49ab2/

UR - https://www.scopus.com/pages/publications/105051196557

U2 - 10.1007/s10762-026-01176-7

DO - 10.1007/s10762-026-01176-7

M3 - Article

VL - 47

JO - Journal of Infrared, Millimeter, and Terahertz Waves

JF - Journal of Infrared, Millimeter, and Terahertz Waves

SN - 1866-6892

IS - 10

ER -