Analytical Gas‐Sensing Responses for Single‐Crystalline Semiconducting Gas Sensors

Abstract

Abstract In this study, an analytical gas response formula is developed based on the classical gaseous molecule adsorption model. To validate the analytical formula, an array of silicon nanowires or microwires is fabricated by patterning the device layer of a silicon‐on‐insulator (SOI) wafer. Gas Hall effect measurements reveal that the surface depletion of the wires narrows down upon exposure to polar molecules that act as dipoles to partially neutralize the surface charges. Gas conductance measurements are performed on different sizes of wires at elevated temperatures. The responses on exposure to different concentrations of water, acetone, and ethanol vapors can be well fitted with the analytical gas response formula. The extracted parameters are consistent with their physical nature. Additionally, the established analytical gas response formula can also well fit gas responses of single‐crystalline nanowires in literature, which further validates the analytical formula.

Keywords

• analytical gas response
• gas Hall effect
• gas‐sensing mechanism
• gas sensors
• silicon nanowires