Fabrication of Spectrally Selective Multinary Thin Nanofilms on Glass as Infra-Red Reflectors for Heat Control Inside Buildings

A. I. Onyia, M. N. Nnabuchi

Abstract: We have fabricated spectrally selective multinary thin nanofilms as good infra-red reflectors for heat control application in buildings and car cabins in both hot and cold climates. Crystalline thin films of Sb-SnO2/SiO2 were grown on plane glass substrates using chemical bath deposition (CBD) techniques. Two CBD baths were used, one to grow silica on glass and the other to grow antimony-doped stannic oxide on top of the silica to form composite multinary and stack heterojunction glass coating that is highly infra-red reflecting. Simple chemicals were used which included SiCl4, NaOH, SnCl4, triethanolamine and distilled water. Thin film formation was a slow pyrolysis precipitation and coalescence of crystal grains into a continuous polycrystalline deposits on glass which were specifically identified by x-ray diffraction done on the films. The elemental, and optical characterization done on the films deciphered film elements in their percentages and showed that the films are high in transmittance (60 - 80 %) in the visible spectrum and also high, up to 80 % in reflectance, in the infra-red ranges thus making our fabrication good candidates for heat controls inside buildings and car cabins.

Keywords: Infra-red, Reflectors, Chemical bath technique, optical analysis, selective surfaces