Highly Efficient NO2 Sensors Based on Al-ZnOHF under UV Assistance
Xingyu Yao1, Rutao Wang1, Lili Wu1
1Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education and School of Materials Science and Engineering, Shandong University, Jinan 250061, China.
Materials (Basel, Switzerland)
|May 13, 2023
Summary
Aluminum doping and UV light enhance zinc hydroxyfluoride
Area of Science:
- Materials Science
- Semiconductor Research
- Chemical Sensing
Background:
- Zinc hydroxyfluoride (ZnOHF) is a novel resistive semiconductor gas-sensing material.
- ZnOHF exhibits inherent selectivity towards nitrogen dioxide (NO2) due to its unique energy band structure.
Purpose of the Study:
- To enhance the gas-sensing performance of ZnOHF.
- To investigate the combined effects of Al3+ doping and UV radiation on ZnOHF.
Main Methods:
- Al3+ doping of ZnOHF at optimized concentrations (0.5 at.%).
- Gas sensing measurements under UV irradiation at various temperatures.
- Analysis of gas-sensing mechanisms, including electron transfer and bandgap modification.
Main Results:
- The optimized 0.5 at.% Al-ZnOHF sample showed improved sensitivity to 10 ppm NO2 at 100 °C under UV light.
- Enhanced gas-sensing performance included a rapid response (35 s) and recovery (96 s) time.
- Al3+ doping reduced the bandgap, increasing electron concentration and facilitating electron transfer.
Conclusions:
- Synergistic effects of Al3+ doping and UV radiation significantly boost ZnOHF gas-sensing performance.
- UV irradiation generates photogenerated electrons and holes, creating new reaction pathways for gas adsorption/desorption.
- The modified ZnOHF demonstrates potential for highly sensitive and selective NO2 detection at lower temperatures.
