“…As a result, the material absorbs the incident light and emits blue light according to the energy gap . WO 3 films can be deposited by various techniques, such as chemical vapor deposition, sputtering, thermal evaporation, electron beam evaporation, hydrothermal processes, spray pyrolysis, sol–gel processes, etc. Among them, sputtering is an industrially adaptable process, as the surface morphology, crystal structure, chemical composition, and electrical properties can be controlled by various parameters, such as the pressure, oxygen content, temperature, deposition time, etc.…”