High-Performance Humidity Sensing of Arsenic Based Chalcogenide Thin Films at Different Frequencies

Present paper consists of the study of arsenic-based chalcogenide thin film for sensing elements for humidity sensors. The chemical composition of the prepared sensing element makes it more sensitive towards water molecule absorption and hence affects sensitivity. The bulk samples of Ge-Se-Te-As composition were prepared using the conventional melt-quench technique and the thin films were obtained using the thermal evaporation method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the structural characteristics of the prepared sensing element. Tauc's plot, using UV-Vis spectrophotometer data, was used to determine the optical bandgap of the sensing materials. The relative humidity (RH) variation of the prepared sensing element was recorded in the range of 10%-90%. The sensitivity of the prepared sensing membrane was obtained as 8.54 M Omega/%RH, 9.724 M Omega/%RH, 10.257 M Omega/%RH for x = 10, 20, 30 respectively. The repeatability of the prepared samples was also reported to increase with Arsenic concentration.

Automated summary

This study investigates the use of arsenic-based chalcogenide thin film as sensing elements for humidity sensors, demonstrating increased sensitivity towards water molecule absorption. Structural characteristics of the prepared sensing element were analyzed using XRD and SEM, with optical bandgap determined through Tauc's plot. The sensitivity of the sensing membrane was found to increase with arsenic concentration, showing good repeatability.