Temperature-Modulated UV-Enhanced SnO2 Gas Sensor Cell With High-Stability and High-Selectivity Gas Discrimination

This article presents a low-power, temperature-modulated gas sensor cell based on tin dioxide, aimed at improving the selectivity of single-material metal oxide gas sensors. This gas sensor cell features hexagonal-structured six channels sharing a heater and six pairs of detecting electrodes sharing a single ground pad, significantly enhancing device integration. The proposed gas sensor cell uses a coplanar design of the heater and detecting electrodes with differential temperature gradients across six detection channels. By precisely designing the temperature distribution across the active regions of the six channels, the selectivity of the tin dioxide sensor cell is greatly enhanced. Furthermore, periodic ultraviolet (UV) light illumination improves the sensor’s response speed and achieves gas discrimination by analysis of the sensitivities instead of whole curves. With the trend toward highly integrated microelectromechanical system (MEMSs) sensor, temperature modulation and UV enhancement hold promise for portable sensor monitoring.