A theoretical investigation of the power-law response of metal oxide semiconductor gas sensors Ι: Schottky barrier control

Hua, Zhongqiu; Li, Yan; Yan, Zhenlin; Wu, Yi

doi:10.1016/j.snb.2017.08.206

Cited by 85 publications

(38 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When an oxidizing target molecule, NO 2 , is introduced to the surface of the oxygen adsorbed site, the following reaction leads to the release of electrons trapped by oxygen to the conduction band of SnO 2 and are trapped again by NO 2 (Figure a). Therefore, surface charge density cannot be influenced by the presence of NO 2 , which is referred to as the shielding effect . The possible chemical interaction can be described as follows

({normalSn}_{normallat} - O_{2}^{-}) + {NO}_{2} \leftrightarrow ({normalSn}_{normallat} - {normalNO}_{2}^{-}) + {normalO}_{2}

…”

Section: Resultsmentioning

confidence: 99%

Ionic‐Activated Chemiresistive Gas Sensors for Room‐Temperature Operation

Song

Shim

Suh

et al. 2019

Small

View full text Add to dashboard Cite

extensively studied because of their remarkable advantages including low cost, simple fabrication, high response, and easy integration with electronic circuits. To ensure high response and reversible operation of chemiresistive gas sensors, high operating temperatures of 150-400 °C are inevitably required for adsorption and desorption of target molecules on and off of the sensing materials. [3,4] However, this high temperature degrades the sensor stability and lifetime due to thermally induced grain growth, which can damage interconnected electronics. [5,6] Moreover, high power consumption (over ≈100 mW) is required, which must be decreased for the development of future battery-powered wireless sensors for applications to the IoT. [7] To design high performance gas sensors that operate at room temperature, a variety of approaches including self-heating, ultraviolet (UV)-assisted measurements, and 2D materials have been used for high stability and low power consumption. [8][9][10] Despite these extensive efforts, challenges remain including poor response and incomplete recovery because of the restricted modulation in electronic conductivity by insufficient reaction energy between the analytes and sensing materials. Recently, the utilization of humidity has been reported as an effective method for improving gas sensing performance at low temperatures.The development of high performance gas sensors that operate at room temperature has attracted considerable attention. Unfortunately, the conventional mechanism of chemiresistive sensors is restricted at room temperature by insufficient reaction energy with target molecules. Herein, novel strategy for room temperature gas sensors is reported using an ionic-activated sensing mechanism. The investigation reveals that a hydroxide layer is developed by the applied voltages on the SnO 2 surface in the presence of humidity, leading to increased electrical conductivity. Surprisingly, the experimental results indicate ideal sensing behavior at room temperature for NO 2 detection with sub-parts-per-trillion (132.3 ppt) detection and fast recovery (25.7 s) to 5 ppm NO 2 under humid conditions. The ionic-activated sensing mechanism is proposed as a cascade process involving the formation of ionic conduction, reaction with a target gas, and demonstrates the novelty of the approach. It is believed that the results presented will open new pathways as a promising method for room temperature gas sensors. Sensors/BiosensorsThe ORCID identification number(s) for the author(s) of this article can be found under https://doi.

show abstract

({normalSn}_{normallat} - O_{2}^{-}) + {NO}_{2} \leftrightarrow ({normalSn}_{normallat} - {normalNO}_{2}^{-}) + {normalO}_{2}

…”

Section: Resultsmentioning

confidence: 99%

Ionic‐Activated Chemiresistive Gas Sensors for Room‐Temperature Operation

Song

Shim

Suh

et al. 2019

Small

View full text Add to dashboard Cite

show abstract

“…The sensing properties were characterized with NO 2 ranging from 0.2 to 5 ppm balanced with syntheses with an operation temperature of 200-350 • C. According to previous reports, chemiresistive type sensors with a low concentration of carriers, i.e., holes in the present case, have a strong transduction ability with high cost of resistance (Bârsan et al, 2010;Hua et al, 2018a). It is worth noting that two identical sensor devices fabricated from the same materials were measured; however, only one sensors' data was presented for simplicity.…”

Section: Resultsmentioning

confidence: 89%

NO2 Sensing Properties of Cr2WO6 Gas Sensor in Air and N2 Atmospheres

Meng

Tian

et al. 2020

Front. Chem.

Self Cite

View full text Add to dashboard Cite

Gas sensors were fabricated from Cr 2 WO 6 nanoparticles for NO 2 detection. Low dimensional materials Cr 2 WO 6 were prepared by a wet chemistry method followed by hydrothermal treatment. The morphology of the nanoparticles and their sensing properties to NO 2 were investigated in both dry and humid conditions. Additionally, the sensing response was also characterized in a non-oxygen condition. It was concluded that the sensor responses in N 2 conditions were higher than that in air conditions at 200 • C. Moreover, the sensing characteristics were inhibited by water vapor at 200 • C. The oxygen adsorption behavior was also investigated to verify the basic sensing mechanism of Cr 2 WO 6 in the absence and presence of NO 2 and water vapor separately. Based on the power law response, it was indicated that both NO 2 and water vapor have a strong adsorption ability than oxygen ions of Cr 2 WO 6 sensors.

show abstract

“…Several studies reported that the photodetection of metal oxide nanostructured sensors is strongly dependent on the ambient gas conditions, with significant differences regarding measurements in air, vacuum or inert gases [97][98][99]. bulk, respectively, EF is the Fermi level, eis the conducting electrons and + the donor positions [49,85]. (b) Schemes of the structural and band models of a n-type semiconductor, and (c) and (b) dark and UV irradiation processes [71,88].…”

Section: O2(g)] (Figures 3 (C) and (D))mentioning

confidence: 99%

“…(b) Schemes of the structural and band models of a n-type semiconductor, and (c) and (b) dark and UV irradiation processes [71,88]. Reproduced with permission MDPI [71], and Elsevier [49], [85] and [88] (2018).…”

Section: O2(g)] (Figures 3 (C) and (D))mentioning

confidence: 99%

Metal oxide nanostructures for sensor applications

Nunes

Pimentel

Gonçalves

et al. 2019

Semicond. Sci. Technol.

223

119

View full text Add to dashboard Cite

Human health, environmental protection and safety are just a few examples of current humankind main concerns, that drive the scientific community to develop sensors able to precisely monitor and alert to possible harms in real time. Over the years, semiconductor metal oxide-based materials have been largely employed as sensors dedicated to several applications, being particularly interesting at the nanometer scale, since it is largely known that smaller crystallite size enhances sensor's performance. Moreover, these materials are highly appealing as they can be produced by low-cost wet-chemical synthesis routes and are in general nontoxic, earth abundant and low-cost. This manuscript extensively reviews the recent developments of nanostructured semiconductor metal oxide sensors ranging from gas to humidity sensors, including ultraviolet (UV) sensors and biosensors. Zinc oxide (ZnO), titanium dioxide (TiO2), tungsten trioxide (WO3), copper oxide (CuO and Cu2O), tin oxide (SnO and SnO2), and vanadium oxide (VO2, V2O5)-based sensors either as nanoparticles or as continuous films/layers are described. Their sensing properties are correlated to size, shape, presence of defects, doping elements, amongst other relevant parameters. Different techniques and methods of fabricating these materials are addressed. The review is concluded with novel approaches for functionalization and future perspectives for sensor developments.

show abstract

A theoretical investigation of the power-law response of metal oxide semiconductor gas sensors Ι: Schottky barrier control

Cited by 85 publications

References 28 publications

Ionic‐Activated Chemiresistive Gas Sensors for Room‐Temperature Operation

Ionic‐Activated Chemiresistive Gas Sensors for Room‐Temperature Operation

NO2 Sensing Properties of Cr2WO6 Gas Sensor in Air and N2 Atmospheres

Metal oxide nanostructures for sensor applications

Contact Info

Product

Resources

About