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Title: Chemiresistive gas sensors employing solution-processed metal oxide quantum dot films

We report low-temperature chemiresistive gas sensors based on tin oxide colloidal quantum dots (CQDs), in which the benefits of CQDs such as extremely small crystal size, solution-processability, and tunable surface activity are exploited to enhance the gas-sensing effect. The sensor fabrication is simply employing spin-coating followed by a solid-state ligand exchange treatment at room temperature in air ambient. The optimal gas sensor exhibited rapid and significant decrease in resistance upon H{sub 2}S gas exposure when operated at 70 °C, and it was fully recoverable upon gas release. We observed a power law correlation between the sensor response and H{sub 2}S gas concentration, and the sensing mechanism was discussed using the completely depletion model with a flat band diagram.
Authors:
; ; ; ; ; ;  [1] ; ; ; ;  [2]
  1. School of Optical and Electronic Information, Huazhong University of Science and Technology, 1037 Luoyu Rd., Wuhan, Hubei 430074 (China)
  2. Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, 1037 Luoyu Rd., Wuhan, Hubei 430074 (China)
Publication Date:
OSTI Identifier:
22350977
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 16; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COLLOIDS; CORRELATIONS; CRYSTALS; ELECTRIC CONDUCTIVITY; ELECTRONIC STRUCTURE; FILMS; GASES; HYDROGEN SULFIDES; ION EXCHANGE; METALS; QUANTUM DOTS; SENSORS; SOLIDS; SPIN-ON COATING; SURFACE PROPERTIES; SURFACES; TEMPERATURE RANGE 0273-0400 K; TIN OXIDES