scholarly journals A THz Spectrometer Using Band Pass Filters

Instruments ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 24
Author(s):  
Francesco Martini ◽  
Ennio Giovine ◽  
Fabio Chiarello ◽  
Pasquale Carelli
Keyword(s):  
Room Temperature ◽  
High Sensitivity ◽  
Black Body ◽  
Spectroscopic Measurements ◽  
Pyroelectric Sensor ◽  
Infrared Spectrometer ◽  
Band Pass ◽  
Economical Alternative

We describe a THz spectrometer operating between 1.2 and 10.5 THz, consisting of band pass filters made by metasurfaces. The source is made of a 10 W small black body. The detector is a high sensitivity room temperature pyroelectric sensor. Various techniques that are used to prepare samples are described. The spectra obtained are compared with those measured with a Fourier Transformer Infrared Spectrometer on the same samples. Our instrument, which uses commercial technologies available at the present time, can constitute an economical alternative to very expensive spectrometers. It has already been successfully used, obtaining precise spectroscopic measurements on many inorganic powders.

UV-assisted High-sensitivity Room-temperature Pd-gated HEMT NO2Gas Sensor

2021 ◽  
Author(s):  
Chong Xing ◽  
Dongcheng Xie ◽  
Haochen Zhang ◽  
Kang Song ◽  
Lei Yang ◽  
...  
Keyword(s):  
Room Temperature ◽  
High Sensitivity

scholarly journals Fabrication of Graphene Nanomesh FET Terahertz Detector

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 641
Author(s):  
Yuan Zhai ◽  
Yi Xiang ◽  
Weiqing Yuan ◽  
Gang Chen ◽  
Jinliang Shi ◽  
...  
Keyword(s):  
Room Temperature ◽  
Energy Gap ◽  
Coupling Efficiency ◽  
High Sensitivity ◽  
Fabrication Process ◽  
Monolayer Graphene ◽  
Terahertz Waves ◽  
Wet Process ◽  
Graphene Nanomesh ◽  
Thz Detector

High sensitivity detection of terahertz waves can be achieved with a graphene nanomesh as grating to improve the coupling efficiency of the incident terahertz waves and using a graphene nanostructure energy gap to enhance the excitation of plasmon. Herein, the fabrication process of the FET THz detector based on the rectangular GNM (r-GNM) is designed, and the THz detector is developed, including the CVD growth and the wet-process transfer of high quality monolayer graphene films, preparation of r-GNM by electron-beam lithography and oxygen plasma etching, and the fabrication of the gate electrodes on the Si3N4 dielectric layer. The problem that the conductive metal is easy to peel off during the fabrication process of the GNM THz device is mainly discussed. The photoelectric performance of the detector was tested at room temperature. The experimental results show that the sensitivity of the detector is 2.5 A/W (@ 3 THz) at room temperature.

Evaluation Humidity Sensing Properties of Graphene/HS-TiO2 Nanocomposites

2021 ◽  
Vol 21 (10) ◽  
pp. 5143-5149
Author(s):  
Zhen Zhu ◽  
Wang-De Lin
Keyword(s):  
Room Temperature ◽  
Response Times ◽  
Sol Gel ◽  
Hollow Spheres ◽  
High Sensitivity ◽  
Humidity Sensing ◽  
X Ray ◽  
Transmission Electron ◽  
Recovery Times ◽  
Relative Humidity Range

This paper reports on a nanocomposite synthesized by sol–gel procedure comprising graphene sheets with hollow spheres of titanium dioxide (G/HS-TiO2) with varying weight percentages of graphene for the purpose of humidity sensors. The surface morphology of the nanocomposite was characterized using transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). The structural properties were examined using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). The response to 12–80% RH at room temperature exhibited sensitivity (S = 135). However, the relative humidity range of 12–90% at room temperature exhibited higher sensitivity (S = 557). Sensors fabricated using the proposed nanocomposite exhibited high sensitivity to humidity, high stability, rapid response times, and rapid recovery times with hysteresis error of less than 1.79%. These results demonstrate the outstanding potential of his material for the monitoring of atmospheric humidity. This study also sought to elucidate the mechanisms underlying humidity sensing performance.

Porous ZnO/rGO Nanosheet‐Based NO 2 Gas Sensor with High Sensitivity and ppb‐Level Detection Limit at Room Temperature

2021 ◽  
pp. 2101511
Author(s):  
Ziwei Chen ◽  
Haojie Guo ◽  
Fusheng Zhang ◽  
Xiaowen Li ◽  
Jiabing Yu ◽  
...  
Keyword(s):  
Detection Limit ◽  
Gas Sensor ◽  
Room Temperature ◽  
High Sensitivity

Exploiting Free-Standing p-CuO/n-TiO2 Nanochannels as a Flexible Gas Sensor with High Sensitivity for H2S at Room Temperature

ACS Sensors ◽  
2021 ◽  
Vol 6 (9) ◽  
pp. 3387-3397
Author(s):  
Haoxuan He ◽  
Chenxi Zhao ◽  
Jing Xu ◽  
Kuanzhi Qu ◽  
Zhen Jiang ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Room Temperature ◽  
High Sensitivity ◽  
Free Standing

A miniature room temperature formaldehyde sensor with high sensitivity and selectivity using CdSO4 modified ZnO nanoparticles

RSC Advances ◽  
2015 ◽  
Vol 5 (92) ◽  
pp. 75098-75104 ◽  
Author(s):  
Xinghua Chang ◽  
Mi Peng ◽  
Junfeng Yang ◽  
Teng Wang ◽  
Yu liu ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Room Temperature ◽  
High Sensitivity ◽  
Sensitivity And Selectivity ◽  
Modified Zno Nanoparticles

A light activated miniature formaldehyde sensor working at room temperature is fabricated by CdSO4 modified ZnO nanoparticles.

Nanocrystalline tungsten oxide thick-films with high sensitivity to H2S at room temperature

2001 ◽  
Vol 77 (1-2) ◽  
pp. 316-321 ◽  
Author(s):  
J.L. Solis ◽  
S. Saukko ◽  
L.B. Kish ◽  
C.G. Granqvist ◽  
V. Lantto
Keyword(s):  
Tungsten Oxide ◽  
Room Temperature ◽  
Thick Films ◽  
High Sensitivity

Broadband terahertz dielectric measurement based on multi-beam interference and Fourier transform infrared spectrometer

2018 ◽  
Vol 32 (25) ◽  
pp. 1850298
Author(s):  
Jie Shi ◽  
Mao-Rong Wang ◽  
Kai Zhong ◽  
Chu Liu ◽  
Jia-Lin Mei ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Room Temperature ◽  
Fourier Transform Infrared ◽  
Refraction Index ◽  
Good Alternative ◽  
Dielectric Measurement ◽  
Terahertz Time Domain Spectroscopy ◽  
Fourier Transform Infrared Spectrometer ◽  
Limited Frequency ◽  
Infrared Spectrometer

We demonstrate a method for obtaining optical coefficients over a broad terahertz spectral range from 1.5 THz to 16 THz at room temperature. Based on the interferograms directly acquired by a Fourier transform infrared spectrometer (FTIR), multi-beam interference principle combining Fresnel’s formula is employed to extract the refraction index and the extinction coefficient, giving the basis for calculating dielectric coefficients. It avoids the uncertainty and phase instability while using Kramers–Kronig (KK) relations and overcomes the limited frequency range of terahertz time-domain spectroscopy (TDS). Moreover, this method has better stability and is needless of cutting useful information between neighboring interference peaks for thin samples compared with TDS, making it a general processing method for interferograms and a good alternative for terahertz dielectric measurement.

scholarly journals A Novel Type Room Temperature Surface Photovoltage Gas Sensor Device 

2018 ◽  
Author(s):  
Monika Kwoka ◽  
Michal A. Borysiewicz ◽  
Pawel Tomkiewicz ◽  
Anna Piotrowska ◽  
Jacek Szuber
Keyword(s):  
Gas Sensor ◽  
Room Temperature ◽  
Gas Sensing ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Fast Response ◽  
Surface Photovoltage ◽  
Kelvin Probe ◽  
Sensor Device ◽  
Developed Surface

In this paper a novel type of a highly sensitive gas sensor device based on the surface photovoltage effect is described. The developed surface photovoltage gas sensor is based on a reverse Kelvin probe approach. As the active gas sensing electrode the porous ZnO nanostructured thin films are used deposited by the direct current (DC) reactive magnetron sputtering method exhibiting the nanocoral surface morphology combined with an evident surface nonstoichiometry related to the unintentional surface carbon and water vapor contaminations. Among others, the demonstrated SPV gas sensor device exhibits a high sensitivity of 1 ppm to NO2 with a signal to noise ratio of about 50 and a fast response time of several seconds under the room temperature conditions.

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