• V KUMAR

      Articles written in Bulletin of Materials Science

    • Influence of defect chemistry on NO$_2$ gas sensing of Li-ZnO thin films

      K K JASMI T ANTO JOHNY V S SIRIL V KUMAR K N MADHUSOODANAN

      More Details Abstract Fulltext PDF

      In this study, we explore the influence of Li dopant on the morphological, electrical and structural properties of ZnO thin films employed for gas-sensing applications. The deposited thin-film gas sensors were evaluated using X-ray diffraction, field-emission scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), and Hall measurements to assess the chemical and physical features of Li-ZnO thin-film gas sensors. All films are crystallized with hcpstructure confirmed from X-ray diffraction analysis. From field-emission scanning electron microscopy analysis, spherical and uneven distribution of particles is observed in all the thin-film samples. The conductivity of the thin-film gas sensorsobtained from the Hall-measurement system shows that all samples except 5wt%Li-ZnO exhibit n-type conductivity. XPS studies confirmed the presence of defect states in all deposited samples. Enhanced nitrogen dioxide (NO$_2$) gas-sensing properties by incorporating an alkali metal (Li, 1–10 wt%) in ZnO were explored. Gas sensing measurements reveal that 1wt% Li-ZnO thin films exhibit remarkable sensitivity (20.94) and fast response/recovery (3s/112s) time towards 45 ppm of NO$_2$ gas. The results are discussed with the influence of defect density states in ZnO and correlated with structural, morphological and electrical parameters.

  • Bulletin of Materials Science | News

    • Dr Shanti Swarup Bhatnagar for Science and Technology

      Posted on October 12, 2020

      Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
      Chemical Sciences 2020

      Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
      Physical Sciences 2020

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2022-2023 Indian Academy of Sciences, Bengaluru.