Abstract: The present paper reports the study of modulation in light transmitted through nanostructured cupric oxide thin films with the exposure of moisture at room temperature. For this purpose the precursor of CuO was prepared and was then investigated using SEM and UV-visible absorption techniques. SEM showed the porous nature of the material and energy band-gaps were estimated as 2.8-3.2 eV for different concentrations by UV-Vis spectrophotometer. The precursor of CuO in the form of gel was prepared and later used for the deposition of thin film on borosilicate substrates with dimensions 1.51.5 cm2 using sol-gel spin coating technique. The film was employed as transmission based opto-electronic humidity sensor. Maximum sensitivity was found 0.85 W/%RH. As the investigated opto-electronic sensor has remote access capability, therefore, may be used to replace an electrical humidity sensor.

Keywords: Nanostructure, opto-electronic humidity sensor, sol-gel spin coating, cupric oxide.