Abstract
In this study, the sensitivity of ZnO thin films to humidity is examined using an optical method. A precursor solution for ZnO film is prepared using the sol–gel process. Sensing elements were fabricated by spin coating different numbers of layers on separate prisms and subsequently annealing them. The sensing mechanism is the modulation of light intensity reflected from the glass–film interface as the relative humidity in the ambient air changes. The change in sensing with variation in number of layers is substantiated by theoretical calculations. Infrared studies, thermal gravimetric analysis, and differential thermal analysis of the precursor films was performed. The ZnO films are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical transmission. SEMs studies confirm the presence of pores which are instrumental in adsorbing water vapour, thereby influencing the refractive index of the films. In the present opto-electronic sensing configuration described herein, a change of 0.09 RH% per unit change in emergent light intensity can be detected.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
