Sol–gel processed zinc oxide film deposited on equilateral prism as optoelectronic humidity sensor

Abstract EN

Zinc oxide film has been deposited on an equilateral prism using spin coating method.

The sample is then annealed at (400) 0C for one hour.

X-ray diffraction (XRD) confirms the formation ZnO polycrystalline structure with the unit cell parameters of a= (0.325) nm and c= (0.52) nm.

The variations of both the transmittance and orbance with wavelength in the range from (300) to (1100) nm is measured.

The optical energy gap of the film is calculated from analysis of optical orption.

Based on output power modulation of reflected laser light, the humidity sensing of the deposited film is investigated at relative humidity (% RH) in the range (10–90) % .

Three angles (45, 60 and 80) degree are used to apply the laser beam.

The obtained results showed that the output power of reflected beam is increased with humidity.

Maximum relative humidity was recorded at incidence angle Өi = (80) degree.