Journal of the Korean Solar Energy Society (한국태양에너지학회 논문집)

The Korean Solar Energy Society (한국태양에너지학회)
권호 표지
DOI QR코드

DOI QR Code

Thermal Degradation of Black Cobalt Solar Selective Coatings

흑색 코발트 태양 선택흡수막의 열퇴화

  • Received : 2015.05.14
  • Accepted : 2015.07.14
  • Published : 2015.08.30
Download PDF
⟨ Previous Next ⟩

Abstract

Black cobalt solar selective coatings were prepared by using an electroplating method. The changes in the optical properties of the black cobalt selective coating due to thermal degradation were analyzed by using the Auger electron spectroscopy (AES) and spectrophotometer. The black cobalt selective coating was prepared on a copper substrate by using a synthesized electrolyte with $CoCl_2$ and KSCN at a current density of ${\sim}0.5A/dm^2$ for 45s ~ 60s. Its optical properties were a solar absorptance (${\alpha}$) of the order of 0.80 ~ 0.84 and a thermal emittance (${\epsilon}$) of 0.01. From the AES depth profile analysis of heated sample, thermal degradation of the black cobalt selective coating heated for 33 hours at temperature of $350^{\circ}C$ occurred primarily due to interdiffusion at interface of cobalt and copper substrate. This results were predictable that the ${\alpha}$ decreases due to the thermal oxidation and diffusion.

Keywords

References

  1. Agnihotri O.P. and Gupta B.K., Solar Selective Surfaces, 1st ed., Wiley-Interscience Publication, New York, 1981, Chapter 5.
  2. Smith G.B., Zajac G., Ignatiev A and Rabalais J.W., Surface composition of selective black chrome films as determined by SIMS, Surface Science, Vol.114, pp.614-626, 1981.
  3. Lee K.D., Optical properties and structure of black cobalt solar selective coating society, Vol.31, pp.48-56, 2011.
  4. Zajac G., Smith G.B. and Ignatiev A., Refinment of solar absorbing black chrome microstructure and its relationship to optical degradation mechanism, Journal of Applied Physics, Vol.51, pp.5544-5554, 1980. https://doi.org/10.1063/1.327475
  5. Lee K.D., Characterization of black cobalt solar selective coatings, Journal of the Korean Physical. Society, Vol.57, pp.111-119. 2010. https://doi.org/10.3938/jkps.57.111
  6. Wang X.J., Jiang L.J., Du D., Kao L., Liu, X.P. and Yu Q.H., The degradation of solar thermal absoprption coatings, Energy Procedia Vol.49 pp.1747-1755, 2014. https://doi.org/10.1016/j.egypro.2014.03.185
  7. Smith G.B., Ignatiev A. and Zajac G., Solar selective black coabalt: preparation, structure, and thermal stability, Journal of Applied Physiscs, Vol.51, pp.4186-4196, 1980. https://doi.org/10.1063/1.328276
  8. Monteiro F.J. and Olivera F., Ageing of black solar selective surfaces, Solar Energy Materials, Vol.21, pp.297-315, 1991. https://doi.org/10.1016/0165-1633(91)90028-J
  9. Selvakumar N. and Barshilia H.C., Review of physical vapor deposited spectrally selective coatings for mid-and high-temperature solar thermal applications, Solar Energy Materials and Solar Cells, Vol.98, pp.1-23. 2012. https://doi.org/10.1016/j.solmat.2011.10.028
  10. Vitt B., Characterization of solar selective black cobalt coating, Sola Energy Materials, Vol.13, pp.323-350, 1996.
  11. Vitt B., Properties of black cobalt coatings, Solar Energy Materials, Vol.19 pp.131-139, 1989. https://doi.org/10.1016/0165-1633(89)90029-4
  12. Duffie J.A. and Beckman W.A., Solar Engineering of Thermal Processes, 2nd., Wiley-Interscience, New York, 1991.
  13. Kane P.E., Characterization of Solid Surfaces, Plenum, New York, 1976, Chapter 20.