ZINC SULFIDE ANTI-REFLECTIVE THIN FILM COATING FOR GERMANIUM OPTICAL WINDOWS

Year 2022, , 36 - 45, 15.06.2022

Abdullah Karaca , Semran Sağlam , Emin Bacaksız , Süleyman Özçelik

https://doi.org/10.55696/ejset.1099149

Abstract

In this work, Anti-reflective thin film is made on Germanium (Ge) optical window, which is one of the most used materials in thermal imaging systems. ZnS material was used its optical transmittance between 2-14 m and due to the fact that it has a refractive index proportional to the refractive index of Ge. ZnS thin films have been prepared by Radio Frequency (RF) magnetron sputtering on Germanium (Ge) optical windows for anti-reflection coating (ARC). ZnS films were produced at different thicknesses using RF sputtering system working pressures under 3, 20 and 30 mTorr. The other RF systems parameters such as RF power, deposition temperature were kept constant for all depositions. Crystal structures, optical and surface properties of ZnS thin films were characterized with X-ray diffraction (XRD), Atomic force microscopy (AFM), Fourier transform ınfrared (FTIR) and UV-VIS transmission spectrometer. The characterization results of Ge optical windows coated ZnS thin films grown at 3 mTorr pressure show that high optical transmission and good crystallinity in ınfrared wavelength region (2-14 um).

Keywords

RF magnetron sputtering, Anti-reflective thin film, ZnS thin film, Growth parameters effect

Supporting Institution

Ministry of Development (TR) and TUBITAK

Project Number

2011K120290 and 115F280

References

• H. A. Macleod, Thin-Film Optical Filters, Fourth ed.: CRC press, London, 2010.
• C. Claeys and E. Simoen, Germanium-based technologies: from materials to devices: Elsevier, p.17, 2011.
• I. Chambouleyron and J. Martínez, "Optical Properties of Dielectric and Semiconductor Thin Films," in Handbook of Thin Films, ed: Elsevier, 2002, pp. 593-622.
• A. Musset and A. Thelen, "IV Multilayer Antireflection Coatings," in Progress in Optics. vol. 8, E. Wolf, Ed., ed: Elsevier, 1970, pp. 201-237.
• J. A. Dobrowolski, "Optical properties of films and coatings," Handbook of optics, vol. 1, pp. 42.3-42.130, 1995.
• R. Gade and T. B. Moeslund, "Thermal Cameras and Applications: a Survey," Machine Vision and Applications, vol. 25, pp. 245-262, 2014.
• J. M. Lloyd, Thermal imaging systems: Springer Science & Business Media, 2013.
• W. C. Dash and R. Newman, "Intrinsic Optical Absorption in Single-Crystal Germanium and Silicon at 77," Physical Review, vol. 99, pp. 1151-1155, 08/15/ 1955.
• A. R. Hilton, "Infrared transmitting materials," Journal of Electronic Materials, vol. 2, pp. 211-225, May 01 1973.
• B. Depuydt, M. De Jonghe, W. De Baets, I. Romandic, A. Theuwis, C. Quaeyhaegens, et al., "Chapter 1 - Germanium Materials," in Germanium-Based Technologies, ed Oxford: Elsevier, 2007, pp. 11-I.
• G. K. Teal and J. B. Little, "Growth of germanium single crystals," in Physical review, 1950, pp. 647-647.
• H. K. Raut, V. A. Ganesh, A. S. Nair, and S. Ramakrishna, "Anti-reflective coatings: A critical, in-depth review," Energy & Environmental Science, vol. 4, pp. 3779-3804, 2011.
• A. Rogalski and K. Chrzanowski, "Infrared devices and techniques," Optoelectronics Review, vol. 10, pp. 111-136, 2002.
• A. Ghosh, P. Kant, P. Bandyopadhyay, P. Chandra, and O. Nijhawan, "Antireflection coating on germanium for dual channel (3–5 and 7.5–10.6 μm) thermal imagers," Infrared physics & technology, vol. 40, pp. 49-53, 1999.
• D. C. Harris, "Durable 3–5 μm transmitting infrared window materials," Infrared physics & technology, vol. 39, pp. 185-201, 1998.
• A. j. Mushtak, "Design of high efficiency multilayer antireflection coatings for visible and infrared substrates," Journal of College of Education, pp. 733-746, 2009.
• P. Klocek, Handbook of infrared optical materials: CRC Press, 2017.
• M. Nadeem, W. Ahmed, and M. Wasiq, "ZnS thin films–an overview," Journal of research science, vol. 16, pp. 105-112, 2005.
• M. Islam, M. Hossain, M. Aliyu, Y. Sulaiman, M. Karim, K. Sopian, et al., "Comparative Study of ZnS Thin Films Grown by Chemical Bath Deposition and Magnetron Sputtering," in Electrical & Computer Engineering (ICECE), 2012 7th International Conference on, 2012, pp. 86-89.
• A. T. Salih, A. A. Najim, M. A. Muhi, and K. R. Gbashi, "Single-Material Multilayer ZnS As Anti-Reflective Coating For Solar Cell Applications," Optics Communications, vol. 388, pp. 84-89, 2017.
• D. Yoo, M. S. Choi, S. C. Heo, C. Chung, D. Kim, and C. Choi, "Structural, optical and chemical analysis of zinc sulfide thin film deposited by RF-mganetron sputtering and post deposition annealing," Metals and Materials International, vol. 19, pp. 1309-1316, November 01 2013.
• S. Firoozifar, A. Behjat, E. Kadivar, S. Ghorashi, and M. B. Zarandi, "A Study of the Optical Properties and Adhesion of Zinc Sulfide Anti-Reflection Thin Film Coated on a Germanium Substrate," Applied Surface Science, vol. 258, pp. 818-821, 2011.
• K. Wasa and S. Hayakawa, "Handbook of sputter deposition technology," p. 177, 1992.
• A. Rolo, O. Conde, M. Gomes, and M. Dos Santos, "Structural, chemical and optical characterisation of Ge-doped SiO2 glass films grown by magnetron rf-sputtering," Journal of Materials Processing Technology, vol. 92, pp. 269-273, 1999.
• C. Cruz-Vázquez, F. Rocha-Alonzo, S. Burruel-Ibarra, M. Barboza-Flores, R. Bernal, and M. Inoue, "A new chemical bath deposition method for fabricating ZnS, Zn (OH) 2, and ZnO thin films, and the optical and structural characterization of these materials," Applied Physics A, vol. 79, pp. 1941-1945, 2004.
• P. Chelvanathan, Y. Yusoff, F. Haque, M. Akhtaruzzaman, M. Alam, Z. Alothman, et al., "Growth and characterization of RF-sputtered ZnS thin film deposited at various substrate temperatures for photovoltaic application," Applied Surface Science, vol. 334, pp. 138-144, 2015.
• D. H. Hwang, J. H. Ahn, K. N. Hui, K. San Hui, and Y. G. Son, "Structural and optical properties of ZnS thin films deposited by RF magnetron sputtering," Nanoscale research letters, vol. 7, pp. 1-7, 2012.
• H. Klug and L. Alexander, "Crystallite size and lattice strains from line broadening," X-ray Diffraction Procedures for Polycrystalline and Amorphous Materials. New York, USA: Wiley-Intersciences, pp. 618-708, 1974.
• L. Whittig and W. Allardice, "X-ray diffraction techniques," Methods of Soil Analysis: Part 1—Physical and Mineralogical Methods, pp. 331-362, 1986.
• F. J. Giessibl, "Advances in atomic force microscopy," Reviews of modern physics, vol. 75, p. 949, 2003.
• M. Caglar, Y. Caglar, and S. Ilican, "The determination of the thickness and optical constants of the ZnO crystalline thin film by using envelope method," Journal of optoelectronics and advanced materials, vol. 8, p. 1410, 2006.
• J. Müllerová and J. Mudro, "Determination of optical parameters and thickness of thin films deposited on absorbing substrates using their reflection spectra," Acta Phys. Slov., vol. 50, pp. 477-488, 2000.