Optimization of ZnO nanorods growth duration for humidity sensing application

Abstract

This paper described an optimization approach of ZnO nanorods growth duration based on humidity sensing scheme. The proposed structure comprises of silica microfiber integrated with Zinc Oxide (ZnO) nanorods coated glass surface. The silica microfiber was tapered into constant waist diameter of 10 µm using flame brushing technique. The glass surface was grown with ZnO nanorods using hydrothermal method for 6 hours, 9 hours, 12 hours, 15 hours and 18 hours growth time. ZnO nanorods growth time would affect morphological structures such as density which change the light absorption into the nanorods. Samples were exposed to the difference humidity level ranging from 35%RH to 85%RH to observe the change of ZnO refractive index on the glass surface resulting different light attenuation in the silica microfiber. It utilizes the unique features of the scattering and surface absorption capability of the microfiber and ZnO nanomaterials coated glass surface to alter the output light intensity. The reported results may contribute to the optimal ZnO nanorods growth time for humidity sensing application.