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Electrothermally Induced Highly Responsive and Highly Selective Vanadium Oxide Hydrogen Sensor Based on Metal–Insulator Transition

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journal contribution
posted on 12.01.2012, 00:00 by Ji Won Byon, Min-Bin Kim, Myung Hwa Kim, Sung Youb Kim, Sang Hyun Lee, Byung Cheol Lee, Jeong Min Baik
We report highly effective hydrogen gas detection based on the metal–insulator transition (MIT) by the electrothermally induced Pd-nanoparticles-decorated vanadium oxide (VO2) nanowire prepared by the efficient and size-controllable growth method originating from V2O5 thin film driven by supercooled liquid nanodroplets. By irradiating a well-defined electron beam into the nanowires, we could significantly increase the conductivity up to four times with only a modest change in the semiconductor-to-metal transition temperature (<2 °C). When exposed to trace amounts of hydrogen gas in a single nanowire configuration, the enhanced conductivity gave rise to about a two times as fast transition to metallic phase even near room temperature (∼35 °C), by reaching much faster (∼3×) a critical current density at which the self-heating initiates. Consequently, we achieved the greatly shorter response time as well as lower operating temperature and voltage for the detection of hydrogen gas in a single VO2 nanowire device, which can be attributed to the self-heating effect accelerated by the increase in the conductivity. The single nanowire sensor also shows the capability of detecting selectively hydrogen of different three gases (O2, CO, and ethylene).