Sensitivity Improvement of Urchin-Like ZnO Nanostructures Using Two-Dimensional Electron Gas in MgZnO/ZnO

So-Young Bak; Jeongseok Lee; Yoojong Kim; Se-Hyeong Lee; Kyoungwan Woo; Sanghyun Lee; Moonsuk Yi

doi:10.3390/s19235195

Sensitivity Improvement of Urchin-Like ZnO Nanostructures Using Two-Dimensional Electron Gas in MgZnO/ZnO

Sensors (Basel). 2019 Nov 27;19(23):5195. doi: 10.3390/s19235195.

Authors

So-Young Bak¹, Jeongseok Lee¹, Yoojong Kim¹, Se-Hyeong Lee¹, Kyoungwan Woo¹, Sanghyun Lee², Moonsuk Yi¹

Affiliations

¹ Department of Electronics Engineering, Pusan National University, Busan 46241, Korea.
² Department of Smart Hybrid Engineering, Pusan National University, Busan 46241, Korea.

Abstract

This paper introduces a strategy for improving the sensitivity of a gas sensor to NO₂ gas. The gas sensor was fabricated using urchin-like ZnO nanostructures grown on MgO particles via vapor-phase growth and decorated with MgZnO nanoparticles via a sol-gel process. The urchin-like ZnO gas sensor decorated with MgZnO showed higher sensitivity to NO₂ gas than a pristine urchin-like ZnO gas sensor. When ZnO and MgZnO form a heterojunction, a two-dimensional electron gas is generated. This improves the performance of the fabricated gas sensor. The growth morphology, atomic composition, and phase structure were confirmed through field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction, respectively.

Keywords: 2DEG; MgZnO; ZnO; gas sensors; sol-gel; vapor phase growth.

Grants and funding

NRF-2019M3F2A1073385/Ministry of Science, ICT