Influence of substrate absorption on accuracy of determination of refractive index and thickness of uniform thin chalcogenide Cu1[As2(S0.5Se0.5)3]99 film

• Published in: Thin solid films 2010-08, Vol.518 (20), p.5679-5682
• Main Authors: STRBAC, D. D, LUKIC, S. R, PETROVIC, D. M, GONZALEZ-LEAL, J. M, SRINIVASAN, A, STRBAC, G. R
• Format: Article
• Language: English
• Subjects: Absorption; Chalcogenides; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Constants; Deposition; Envelopes; Exact sciences and technology; Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Optical properties of specific thin films; Physics; Reflectivity; Refractive index; Thin films; Transmittance
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2009.10.025

The envelope method is a commonly used method for determination of some important optical constants, by using the envelopes of the transmittance T(I') and/or reflectance R(I') spectrum of the thin film deposited on transparent substrate. Two envelope methods were carried out in this paper: standard--method which assumes that substrate is absolutely transparent and modified--method which takes substrate absorption into account. The investigated sample is a uniform thin chalcogenide Cu1[As2(S0.5Se0.5)3]99 film, deposited onto two kinds of a weakly absorbing substrates that differ in thickness. It was shown that the degree of accuracy in determination of chosen optical parameters for both investigated samples is notably improved when the absorbance of the bare substrates is considered in the expressions for the envelopes.