Preparation and Bolometric Responses of MoS2 Nanoflowers and Multi-Walled Carbon Nanotube Composite Network

Abstract

Due to their broadband optical absorption ability and fast response times, carbon nanotube (CNT)-based materials are considered promising alternatives to the toxic compounds used in commercial infrared sensors. However, the direct use of pure CNT networks as infrared sensors for simple resistance read-outs results in low sensitivity values. In this work, MoS2 nanoflowers are composited with CNT networks via a facile hydrothermal process to increase the bolometric performance. The thermal diffusivity (α) against temperature (T) is measured using the transient electro-thermal (TET) technique in the range of 320 K to 296 K. The α-T curve demonstrates that the composite containing MoS2 nanoflowers provides significant phonon scattering and affects the intertube interfaces, decreasing the α value by 51%. As the temperature increases from 296 K to 320 K, the relative temperature coefficient of resistance (TCR) increases from 0.04%/K to 0.25%/K. Combined with the enhanced light absorption and strong anisotropic structure, this CNT–MoS2 composite network exhibits a more than 5-fold greater surface temperature increase under the same laser irradiation. It shows up to 18-fold enhancements in resistive responsivity ((Ron − Roff)/Roff) compared with the pure CNT network for a 1550 nm laser at room temperature (RT).

Ultra-Low-Density Carbon Nanotube Aerogel Film for Fast and Sensitive Bolometric Sensing

“…In this work, the suspended length of S7 is 1.22 mm. If the sample suspending length is reduced to 200 μm in the future (the typical size of the pixel unit of a bolometer array), the response time of CAF will be reduced to 1/37 of the original response time, corresponding to 2.95–3.03 ms (framing rate of 330–339 per second). This short response time is due to the ultra-low density of CAF, which is comparable or shorter than the reported response time for MWCNT films (1–2.5 ms), SWCNT films (40–50 ms), and a-Si (11–500 ms) .…”

“…Fast and sensitive infrared (IR) detectors that operate at room temperature are in great demand in various applications such as security, environmental monitoring, remote control, biomedical applications, optical communications, and thermal imaging as well as cutting-edge technologies like smart automobiles and robotic navigation. − Novel nanomaterials such as ZnS, MoS 2 , and WS 2 have been developed for achieving fast, sensitive, and flexible photodetectors in recent years. − Carbon based materials have the advantages of wideband absorption, fast response, good electrical conductivity, low cost, good stability, etc., − which have gained great attention as one of the most promising materials for flexible infrared detectors. − Lu et al reported an absolute temperature coefficient of resistance (TCR) of 0.17%/K for single-walled carbon nanotube (SWCNT) films and 0.07%/K for multi-walled carbon nanotube (MWCNT) films . John et al.…”

Carbon Nanotube-Based Uncooled Bolometers: Advances and Progress

“…Incorporation of MoS 2 added a synergistic effect to the bolometric response by influencing the intertube junctions (leading to a great deal of phonon scattering) and enhancing the optical absorption. 191 Finally, apart from functionalization and using semiconducting nanoparticles (NPs), metal NPs (in particular, Au) have also been used to improve the bolometric response of MWCNT film. 40 recently, studies have also been performed on 3D CNT structures for bolometric IR sensor arrays.…”

“…Copyright 2020, American Chemical Society, Washington, DC. Panel (f) was reproduced with permission from ref . Copyright 2022.…”

“…A TCR ranging from 0.04%/K to 0.25%/K was obtained in the temperature range of 296–320 K (Figure f). Incorporation of MoS 2 added a synergistic effect to the bolometric response by influencing the intertube junctions (leading to a great deal of phonon scattering) and enhancing the optical absorption . Finally, apart from functionalization and using semiconducting nanoparticles (NPs), metal NPs (in particular, Au) have also been used to improve the bolometric response of MWCNT film .…”