The Effect of Thickness of Aluminium Films on Optical Reflectance

Abstract

In Uganda and Africa at large, up to 90% of the total energy used for food preparation and water pasteurization is from fossil fuels particularly firewood and kerosene which pollute the environment, yet there is abundant solar energy throughout the year, which could also be used. Uganda is abundantly rich in clay minerals such as ball clay, kaolin, feldspar, and quartz from which ceramic substrates were developed. Aluminium films of different thicknesses were deposited on different substrates in the diffusion pump microprocessor vacuum coater (Edwards AUTO 306). The optical reflectance of the aluminium films was obtained using a spectrophotometer (SolidSpec-3700/DUV-UV-VIS-NIR) at various wave lengths. The analysis of the results of the study revealed that the optical reflectance of the aluminium films was above 50% and increased with increasing film thickness and wavelength. Thus, this method can be used to produce reflector systems in the technology of solar cooking and other appliances which use solar energy.