Influence of microheater patterns: MoSi2-SnO2 as energy-saving chemiresistors for gas sensing applications

In this article, we study the effect of various geometrical patterns (meander, spiral, and fin shape) of composite MoSi2-SnO2 microheater films towards an energy-saving approach for hydrogen gas sensing. The MoSi2-SnO2 microheater was prepared by using the screen-printing technique on a Si wafer. The structural and microstructural evolution characterization was done by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and field emission scanning electron microscopy (FESEM). The electrical characteristics were assessed by I-V measurements up to 8 V. The Joule heating effect was studied for printed patterns and correlated with the maximum temperature obtained in each case. We have compared the gas sensing properties of the composite MoSi2-SnO2 thin films according to the various geometrical patterns for hydrogen gas. The results show that the fin-shaped microheater provides more heating temperature (120 degrees C) followed by spiral and meander patterns due to a higher resistance change. The fin-shaped microheater pattern showed maximum temperature when operated at the same power levels from 0 to 20 mW. The fin-shaped structure microheater sensor was highly selective and had the optimum response and recovery times of 12 s and 27 s with a detection limit of 0.25 ppm. Based on these observations, the hydrogen sensing mechanism of MoSi2-SnO2 microheaters is discussed and reported here.

Automated summary

This study investigates the impact of various geometric patterns of composite MoSi2-SnO2 microheater films on the energy-saving approach for hydrogen gas sensing. It was found that the fin-shaped microheater provides the highest heating temperature and best gas sensing properties. Juxtapositions were made based on the heat and resistance change of the patterns, with the fin-shaped structure showing the most promising results.