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Determination of the Optimal Sensing Temperature in Pt/Ta2O5/MoO3 Schottky Contacted Nanobelt Straddling Heterojunction

Department of Materials Science and Engineering, City University of Hong Kong, 88 Tat Chee Avenue, Kowloon Tong, Kowloon, Hong Kong
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Author to whom correspondence should be addressed.
Sensors 2018, 18(11), 3770; https://doi.org/10.3390/s18113770
Received: 25 August 2018 / Revised: 2 October 2018 / Accepted: 2 October 2018 / Published: 5 November 2018
(This article belongs to the Section Chemical Sensors)
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Abstract

Nanostructured Schottky barrier gas sensors have emerged as novel semiconductor devices with large surface areas and unique electronic characteristics. Although it is widely known that operating these gas sensors requires heating to an optimal temperature for the highest sensitivity, the fundamental mechanism that governs the temperature-dependent sensitivity has yet been well understood. In this work, we present new evidence to support that thermionic field emission (TFE) is the dominant transport mechanism for Schottky contacted nanostructured heterojunction gas sensors at their optimal sensing temperature. Through the fabrication and characterization of Pt/MoO3 Schottky contacts, and Pt/Ta2O5/MoO3 heterojunctions, we found a previously unreported connection between TFE transport and optimal gas sensing temperature. This connection enables the description of Schottky barrier gas sensing performance using transport theory, which is a major step towards systematic engineering of gas sensors with nanostructured high-k oxide layers. View Full-Text
Keywords: nanobelt; heterojunction; Schottky barrier; Ta2O5; MoO3; optimal sensing temperature nanobelt; heterojunction; Schottky barrier; Ta2O5; MoO3; optimal sensing temperature
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Cheung, K.W.; Yu, J.; Ho, D. Determination of the Optimal Sensing Temperature in Pt/Ta2O5/MoO3 Schottky Contacted Nanobelt Straddling Heterojunction. Sensors 2018, 18, 3770.

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