Controlling the optical constants of thermally-evaporated Ge10Sb30S60 chalcogenide glass films by photodoping with silver

• Published in: Journal of non-crystalline solids Vol. 274; no. 1-3; pp. 62 - 68
• Main Authors: MARQUEZ, E, WAGNER, T, GONZALEZ-LEAL, J. M, BERNAL-OLIVA, A. M, PRIETO-ALCON, R, JIMENEZ-GARAY, R, EWEN, P. J. S
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Amsterdam Elsevier 01.09.2000
• Subjects: Amorphous semiconductors; glasses; Amorphous semiconductors; glasses; nanocrystalline materials; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Physics; Inorganic compounds; Photodoping; Ternary compounds; Refractive index; Glass; Experimental study; Germanium Antimonides sulfides; Thin films; Silver; Chemical bonds; Absorption spectra; Vacuum evaporation; Optical constants
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/S0022-3093(00)00184-8

Authors have analyzed the effect of Ag content on the optical properties of Ag-doped Ge10Sb30S60 chalcogenide glass films; the chalcogenide host layers were prepared by vacuum thermal evaporation. Films of compositions Agx(Ge0.1Sb0.3S0.6)100-x, with x less than or equal to 8 at.%, were obtained by successively photodissolving thin (around 10 nm) layers of Ag. The optical constants (n,k) have been determined by a method based on the envelope curves of the optical transmission spectrum at normal incidence. The dispersion of the refractive index of the Ag-photodoped chalcogenide films is analyzed within the single-effective-oscillator approach. The optical-absorption data indicate that the absorption mechanism is nondirect transition. Authors found that the refractive index of the Ag-doped samples increases with the Ag content, whereas the optical band gap decreases from 1.97plus/minus 0.01 to 1.67plus/minus 0.01 eV. These results are consistent with the hypothesis that the photodoped Ag is a structure modifier in the a-Ge10Sb30S60 films. 19 refs.