Spectroscopic Ellipsometry Investigation of Optical Constants and Dispersion Parameters of TlGaS2 Single Crystals

Date

2026-08-01

Author

Mecit, Giray
Isik, Mehmet
Hasanlı, Nızamı

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

29
views

0
downloads

Cite This

Spectroscopic ellipsometry measurements were performed on freshly cleaved layer-plane (001) surfaces of TlGaS2 crystals, with the surface normal approximately oriented along the reciprocal-lattice direction , in the photon-energy range of 1.2-6.2 eV at room temperature. The measured ellipsometric parameters, acquired at a fixed incidence angle and analyzed using ambient-substrate model, were used to determine the dielectric function as well as the effective refractive index and extinction coefficient for the present oblique-reflection configuration. From these effective optical functions, corresponding absorption coefficient, optical penetration depth, and dielectric-related response functions were derived. The derived absorption spectrum exhibits a pronounced absorption-edge feature near 2.43 eV, as identified from the first derivative of the absorption coefficient with respect to photon energy. The low-energy dispersion behavior was analyzed using Wemple-DiDomenico single-oscillator model. In addition, the surface and volume energy-loss functions were evaluated to further characterize the effective electronic response in the measured geometry. The resulting effective optical parameters provide a configuration-specific description of the optical response of TlGaS2, relevant to optoelectronic and photonic applications. Because TlGaS2 is a monoclinic and optically anisotropic crystal, these quantities do not represent the complete intrinsic dielectric tensor or separately resolved polarization-dependent optical constants of the material.

URI

https://hdl.handle.net/11511/120555

Collections

Department of Physics, Article