Optically Tunable Sensing Performance of Metal Oxide Composites for the Detection of Toxic Industrial Chemicals at Room Temperature

Traditional metal oxide (MOS)-based chemiresistive gas sensors operate at a higher operating temperature and require high power consumption. Due to this high operating temperature, these sensing materials lack chemical stability. One strategy to improve these gas sensors' performance is through nanoengineering of sensing materials by tuning materials morphology and introducing defect structure. However, the sensing performance still suffers due to the lower electron density at the MOS conduction band at room temperature.

The overarching goal is to fabricate a light tunable chemiresistive-type gas sensors using a library of MOS-based nanomaterials and demonstrate the ability to manipulate room temperature sensing performance by adjusting the wavelength and intensity. Therefore, high-density sensing systems (flexible 60 sensors array and 16 MEMS-based system) were integrated with customized optical components for comprehensive room temperature sensing performance investigation. This objective can be achieved by designing a range of n-type and p-type MOS-based gas sensors under ultraviolet (UV) light excitation to demonstrate room temperature analyte detection. Additionally, introducing different MOS nanocomposite combinations by forming n/n and p/n heterojunctions to demonstrate room temperature air pollutant detection under UV excitation. Another strategy to further improve sensing performance is through nanoengineering of sensing materials and sensor architecture, such as introducing optically active materials to enable optical tuning of the sensing materials, known as the localized surface plasmon resonance (LSPR) effect. As a result, visible light integrated room temperature gas sensing could be possible. Overall, for this comprehensive analysis, morphological and structural property investigation and tuning of electrical and chemical properties of the sensing materials will be evaluated.