Gas Sensor Based on Metal−Insulator Transition in VO₂ Nanowire Thermistor

Abstract

Using temperature driven sharp metal-insulator phase transition in single crystal VO(2) nanowires, the realization of a novel gas sensing concept has been tested. Varying the temperature of the nanowire close to the transition edge, the conductance of the nanowire becomes extremely responsive to the tiny changes in molecular composition, pressure, and temperature of the ambient gas environment. This gas sensing analog of the transition edge sensor radiometry used in astrophysics opens new opportunities in gas sensorics.

VO2(B) conversion to VO2(A) and VO2(M) and their oxidation resistance and optical switching properties

“…Over the past decades, numerous efforts have been employed in vanadium oxides and their related compounds as functional materials because of their layered structures, unique chemical and physical properties, which make them highly desired in a wide range of promising potential applications such as catalysts, cathode materials for reversible lithium batteries, gas sensors, intelligent thermochromic windows, electrical and optical devices, laser shield and so on [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. As is well known, vanadium has abundant oxidation states (0 to +5), which usually correspond to a variety of binary oxides with the general formula VO 2 + x (−0.5 x 0.5) [15,16], such as V 2 O 5 , VO 2 , V 2 O 3 , V 3 O 7 , V 4 O 9 , V 6 O 13 , etc.…”

The influence of VO2(B) nanobelts on thermal decomposition of ammonium perchlorate

“…VO 2 (B), one of metastable phases of vanadium dioxide VO 2 , has attracted increasing interest in recent years because of its layered structure and promising properties in the nanometer regime [14][15][16][17][18][19][20][21][22][23]. VO 2 (B) is an attractive material for various applications, especially as an electrode…”

Room temperature vanadium dioxide–carbon nanotube gas sensors made via continuous hydrothermal flow synthesis

“…Monoclinic vanadium dioxide [VO2(M)] is a particularly interesting thermochromic material 11 , with a range of polymorphs that have attracted interest for use in gas sensing [12][13][14][15] . A variety of morphologies have been obtained for vanadium oxides (VOx), including nanofibers 16 , nano-belts 17 , nanorods 12,[18][19][20] and nanowires (NWs) 13 .…”

“…Monoclinic vanadium dioxide [VO2(M)] is a particularly interesting thermochromic material 11 , with a range of polymorphs that have attracted interest for use in gas sensing [12][13][14][15] . A variety of morphologies have been obtained for vanadium oxides (VOx), including nanofibers 16 , nano-belts 17 , nanorods 12,[18][19][20] and nanowires (NWs) 13 . Gas sensors using these nanomaterials have been used for the detection of ammonia (NH3) gas [21][22][23] , nitrogen dioxide (NO2) 24 , ethanol (C2H6O) 17,25 , methane (CH4) 26 and liquefied petroleum gas (LPG) 12 , at both ambient (25 ̊ C) and elevated operating temperatures.…”

“…Gas sensors using these nanomaterials have been used for the detection of ammonia (NH3) gas [21][22][23] , nitrogen dioxide (NO2) 24 , ethanol (C2H6O) 17,25 , methane (CH4) 26 and liquefied petroleum gas (LPG) 12 , at both ambient (25 ̊ C) and elevated operating temperatures. Strelcov et al reported that by operating a VO2 nanowire sensor close to the materials' metal-semiconductor transition temperature (≈ 68 ̊ C), conductance through the material became highly sensitive to the molecular composition of the environment, even enabling the detection of inert gases 13 . Depending on the structures formed and their respective oxidation states, vanadium oxides can also display sensitivity to water (H2O) and are thus suitable for use as humidity sensors 12,14,27,28 .…”