LUT Achieves Breakthrough in MOS Gas Sensing Mechanism, Providing Theoretical Basis for Gas-Sensitive Material Design

Release time：

2025-10-18

Recently, the research team led by young teacher Jinglong Bai and Professor Zhiqiang Wei from the School of Science at Lanzhou University of Technology has made significant progress in studying the gas-sensing mechanism of metal-oxide-semiconductor (MOS). Their research findings, entitled "In Situ PL Tracking the Evolution and Functionality of Oxygen Defects in the In₂O₃-Based NO₂ Gas Sensor," have been published in ACS Sensors (a CAS Q1 TOP journal) and selected as the cover article.

Research demonstrates that oxygen defects (including oxygen vacancies and interstitial oxygen) are among the key factors affecting the gas-sensing performance of metal-oxide-semiconductors (MOS).However, in situ probing of the intrinsic role of oxygen defects during gas sensing has remained a major challenge in this research field.

Professor Jinglong Bai's team at LUT successfully prepared pristine In₂O₃ single-crystal porous nanosheets via hydrothermal method. Through holmium (Ho) and praseodymium (Pr) single-doping and binary doping strategies, they achieved effective modulation of oxygen defect types in the material.

During the research, the team employed in situ photoluminescence (PL) technology to track the dynamic evolution of oxygen defects in real time during the gas sensing response process.Gas sensing tests demonstrated that the Ho/Pr-doped In₂O₃ sensor, operating at lower power consumption, exhibited a significantly increased response value of 37.5 to 10 ppm nitrogen dioxide (NO₂), compared to 8.5 for the pristine material, along with enhanced stability and selectivity.

Critically, through in situ PL analysis, this study unambiguously identified the promoting role of oxygen vacancies in adsorbing oxygen ions and the inhibitory behavior of interstitial oxygen (Oi″), establishing a positive correlation between the gas sensor response value and oxygen vacancy concentration.This discovery provides a crucial theoretical basis and new insights for the rational design of high-performance metal-oxide-semiconductor (MOS) gas-sensing materials.

This research was supported by the National Natural Science Foundation of China, the Gansu Provincial Youth Science and Technology Fund, and the Lanzhou University of Technology "Red Willow Outstanding Youth Talent Support Program".Professor Jinglong Bai is the first author and corresponding author of the paper, with Lanzhou University of Technology (LUT) as the primary affiliation.

Citation: China Electronic Components Association.

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