Analysis and effect of chemically deposited cadmium sulphide (CdS) thin films on solar absorptance and thermal emittance of stainless steel AISI 304 BA 2B

I. L. Atubu, P. A. Ilenikhena, N. A. Itabor, L. E. Damisah and J. O. Olatunji

Physical Sciences Research International
Published: September 29 2014
Volume 3, Issue 3
Pages 44-50

Abstract

Thin films of cadmium sulphide (CdS) were deposited on 24 polished sample plates of stainless steel AISI 304 BA 2B using chemical bath deposition technique for different molar concentrations of CdS in bath solution at a fixed deposition time and also for a fixed concentration of CdS at different deposition times. The average thermal emittance values of the polished and coated sample plates were determined before and after the deposition of thin films, respectively. The average thermal emittance and average solar absorptance value of the uncoated polished sample plate is 0.15 ± 0.01 and 0.47 ± 0.01 while average thermal emittance values of the coated sample plates is 0.15 ± 0.01 for those done with varying concentrations of CdS in bath solution and a fixed deposition time and for those done with fixed concentration of CdS in bath solution and varying deposition times. Average solar absorptance values for various and fixed CdS concentrations of the coated sample plates in bath solution, fixed and various deposition times gave 0.47 ± 0.01 and 0.64 ± 0.01, respectively. The film thickness of the coated sample plates varied from 0.21 to 0.61 ± 0.01 µm. These low thermal emittance values compare well with those obtained for oxidized stainless steel selective surfaces. The coated sample plates with most favourable conditions of thermal emittance 0.19 ± 0.01, solar absorptance 0.64 ± 0.01 and film thickness 0.44 ± 0.01 µm could find applications in photothermal conversion of solar energy. The results indicate that the chemical bath deposition technique could be employed to fabricate selective surfaces for use in solar energy applications.

Keywords: Thermal emittance, cadmium sulphide (CdS), solar absorptance, thin films, chemical bath deposition technique.

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