Prospects of chemically deposited CoS-CU2S coatings for solar control applications

Abstract

Good quality thin films of Cu2S were successfully deposited on CoS-precoated glass substrates by the chemical bath deposition process using triethanolamine (TEA) and aqueous ammonia NH3(aq) as complexing agents and Copper II nitrate and thiourea as precursors. The thin films of Cu2S deposited on CoS-precoated glass substrates from chemical baths and annealed at 100oC were found to have desirable solar control characteristics superior to commercial tinted glass and magnetron sputtered multilayer metallic solar control coatings. These include: transmission spectra in the visible region similar to photopic vision spectra, with an integrated transmittance in the range of about 23-28% and an integrated reflectance of about 10-15%, coupled with a range of colours in transmitted and reflected daylight. Moreover, the coating of the glass substrates with a thin layer of CoS prior to Cu2S film deposition was found to improve the mechanical stability of the Cu2S thin films, offering the choice of different shades of colours for the same integrated transmittance in the visible region in solar control applications. The possibility therefore exists for multiple-dip deposition of Cu2S films to enhance the film thickness, enabling the realisation of solar absorber coatings. Key words: CoS – Cu2S Thin Films, Solar Control Coatings, Chemical Deposition (Global Journal of Pure and Applied Sciences: 2003 9(4): 591-598)