Highly selective and sensitive chemoresistive humidity sensors based on rGO/MoS2 van der Waals composites

2018 ◽  
Vol 6 (12) ◽  
pp. 5016-5024 ◽  
Author(s):  
Seo Yun Park ◽  
Yeon Hoo Kim ◽  
Seon Yong Lee ◽  
Woonbae Sohn ◽  
Jung Eun Lee ◽  
...  

Sensors based on 2D rGO/2D MoS2 van der Waals hybrid composites exhibited high sensitivity, extreme selectivity, fast response/recovery, and good reliability to humidity detection.

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 659 ◽  
Author(s):  
Hong Liu ◽  
Qi Wang ◽  
Wenjie Sheng ◽  
Xubo Wang ◽  
Kaidi Zhang ◽  
...  

Recently, humidity sensors have been investigated extensively due to their broad applications in chip fabrication, health care, agriculture, amongst others. We propose a capacitive humidity sensor with a shielding electrode under the interdigitated electrode (SIDE) based on polyimide (PI). Thanks to the shielding electrode, this humidity sensor combines the high sensitivity of parallel plate capacitive sensors and the fast response of interdigitated electrode capacitive sensors. We use COMSOL Multiphysics to design and optimize the SIDE structure. The experimental data show very good agreement with the simulation. The sensitivity of the SIDE sensor is 0.0063% ± 0.0002% RH. Its response/recovery time is 20 s/22 s. The maximum capacitance drift under different relative humidity is 1.28% RH.


Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5118
Author(s):  
Zhenyu Wei ◽  
Jianqiu Huang ◽  
Wenhao Chen ◽  
Qingan Huang

Porous polytetrafluoroethylene (PTFE) is physically flexible, thermally and chemically stable, relatively inexpensive, and commercially available. It is attractive for various flexible sensors. This paper has studied flexible capacitive humidity sensors fabricated on porous PTFE substrates. Graphene oxide (GO) was used as a sensing material, both hydrophobic and hydrophilic porous PTFE as the substrates, and interdigitated electrodes on the PTFE substrates were screen-printed. SEM and Raman spectrum were utilized to characterize GO and PTFE. An ethanol soak process is developed to increase the yield of the humidity sensors based on hydrophobic porous PTFE substrates. Static and dynamic properties of these sensors are tested and analyzed. It demonstrates that the flexible capacitive humidity sensors fabricated on the ethanol-treated hydrophobic PTFE exhibit high sensitivity, small hysteresis, and fast response/recovery time.


2020 ◽  
Vol 8 (10) ◽  
pp. 3386-3394 ◽  
Author(s):  
Baofang Cai ◽  
Huan Yin ◽  
Tingting Huo ◽  
Jun Ma ◽  
Zengfeng Di ◽  
...  

All-carbon van der Waals junction humidity sensors exhibit high sensitivity and millisecond response/recovery times due to efficient charge transfer.


Nanoscale ◽  
2014 ◽  
Vol 6 (12) ◽  
pp. 6521-6525 ◽  
Author(s):  
Ming Zhuo ◽  
Yuejiao Chen ◽  
Tao Fu ◽  
Haonan Zhang ◽  
Zhi Xu ◽  
...  

Ni(SO4)0.3(OH)1.4 nanobelts are utilized in a humidity sensor by a facile method. The nanobelt based sensor shows a high sensitivity, fast response and long-term stability in the sensing process.


2016 ◽  
Vol 52 (54) ◽  
pp. 8417-8419 ◽  
Author(s):  
Lingling Wang ◽  
Xiaochuan Duan ◽  
Wuyuan Xie ◽  
Qiuhong Li ◽  
Taihong Wang

A novel resistance type humidity sensor was fabricated using poly(ionic liquid)s, which exhibited high sensitivity, fast response, small hysteresis and good repeatability at a relative humidity (RH) in the range of 11–98%, making poly(ionic liquid)s as promising sensing materials for high-performance humidity sensors.


2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Nguyen Hai Ha ◽  
Nguyen Hoang Nam ◽  
Dang Duc Dung ◽  
Nguyen Huy Phuong ◽  
Phan Duy Thach ◽  
...  

We report the fabrication and characterization of surface acoustic wave (SAW) hydrogen sensors using palladium-graphene (Pd-Gr) nanocomposite as sensing material. The Pd-Gr nanocomposite as sensing layer was deposited onto SAW delay line sensor-based interdigitated electrodes (IDTs)/aluminum nitride (AlN)/silicon (Si) structure. The Pd-Gr nanocomposite was synthesized by a chemical route and deposited onto SAW sensors by air-brush spraying. The SAW H2 sensor using Pd-Gr nanocomposite as a sensing layer shows a frequency shift of 25 kHz in 0.5% H2 concentration at room temperature with good repeatability and stability. Moreover, the sensor showed good linearity and fast response/recovery within ten seconds with various H2 concentrations from 0.25 to 1%. The specific interaction between graphene and SAW transfer inside AlN/Si structures yields a high sensitivity and fast response/recovery of SAW H2 sensor based on Pd-Gr/AlN/Si structure.


2020 ◽  
Vol 213 ◽  
pp. 02014
Author(s):  
Tianying He ◽  
Changyong Lan ◽  
Chun Li ◽  
Sihan Zhou ◽  
Yi Yin

Van der Waals heterostructure shows promising applications in next generation optoelectronics. As a kind of van der Waals heterostructure, graphene/silicon (Gr/Si) based heterostructure devices have been demonstrated as high performance photodetectors. Here, we studied the origin of the high performance of Gr/Si photodetectors based on photocurrent mapping technology. According to photocurrent mapping, the photocurrent in the Gr/Si and Gr/SiO2/Si area nearing the Si window edge is higher than that in other positions, which is attributed to the highly effective collection efficiency of photocarriers. A device with size of Gr/Si region (r=7.4 μm) and Gr/SiO2/Si region (L=6.1 μm) shows high sensitivity and a broadband photoresponse in the range from 420 to 1000 nm with the peak sensitivity of 52 A/W at 780 nm, and fast response speed with rise time of 16 μs and decay time of 52 μs. Our study provides a strategy for the design of high photoresponsivity Gr/Si based devices.


Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3858
Author(s):  
Shinya Kano ◽  
Harutaka Mekaru

Fast-response humidity sensors using nanomaterials are attractive and have been intensively studied. Among the various nanomaterials, nonporous inorganic nanoparticles are suitable for use in humidity sensitive films for sensors. Here, we focus on a nonporous inorganic nanoparticle film and investigate a humidity sensor using the film. Hysteresis error and a dynamic response to a change of humidity are fundamental specifications of humidity sensors. A humidity sensor using a 50 nm silica nanoparticle film shows a hysteresis error of 2% at 85% RH and a response/recovery time of 2.8/2.3 s in 30% RH to 70% RH. We also summarize response/recovery times and hysteresis errors of state-of-the-art humidity sensors. As compared to those of commercial sensors and porous nanoparticle-based sensors evaluated using saturated salt solutions, the fabricated sensor shows a comparative hysteresis error and shorter response time.


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