Self-doped nanocolumnar vanadium oxides thin films for highly selective NO2 gas sensing at low temperature

Soo Deok Han, Hi Gyu Moon, Myoung Sub Noh, Jung Joon Pyeon, Young Seok Shim, Sahn Nahm, Jin Sang Kim, Kwang Soo Yoo, Chong Yun Kang

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)


Vanadium dioxide (VO2) as strong correlated oxide has been intensively studied due to the unique properties accompanied by metal-insulator transition (MIT) near room temperature. Their extrinsic electrical and optical transformations on MIT have been greatly attracted in many potential applications. In this study, we propose to apply an intrinsic electrical property of VO2 in metallic phase as doping agent of chemiresistive sensor. Self-doped nanocoulmnar vanadium oxides (SNVO) thin films are simply fabricated by glancing angle deposition without any template and chemical additives. The nanocolumnar VO2 thin films were deposited by e-beam evaporator, and then the SNVO with residual VO2 in V2O5 nanocolums were synthesized by an air atmosphere annealing, which are composed of dominant oxidized V2O5 which plays a sensing role on the surface and the residual VO2 with self-doping effect inside nanocolumns. Especially at low temperature (150 °C), SNVO sensor shows an ultra-high performance (Rgas/Rair > 100) to NO2 (5 ppm) gas. It is supposed that the residual VO2 which shows metallic properties above Mott transition temperature (∼67 °C) acts as an intrinsic electron donor by pseudo-free electron, which helps adsorption of oxygen ions on the surface and extends the depletion region of few nanometers of narrow necks between nanocolumns.

Original languageEnglish
Pages (from-to)40-47
Number of pages8
JournalSensors and Actuators, B: Chemical
Publication statusPublished - 2017 Mar 31

Bibliographical note

Funding Information:
This work was supported by Institute for Information & communications Technology Promotion (IITP) grant funded by the Korea government (MSIP) (No. R0126-16-1050 , Olfactory Bio Data based Emotion Enhancement Interactive Content Technology Development), the Institutional Research Program of the Korea Institute of Science and Technology ( 2E25440 ), and KU-KIST Research Program of Korea University ( R1435271 ).


  • Gas sensor
  • Glancing angle deposition
  • Nanocolumnar thin films
  • Self-doping
  • Vanadium oxides

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry


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