Exploring the Linear and Nonlinear Optical Behavior of (TlInS2)0.75(TlInSe2)0.25: Insights from Ellipsometry Measurements

Işık, Mehmet
Güler, İpek
Gasanly, Nizami Mamed
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Physica B: Condensed Matter
The search for layered structured new semiconductor materials with remarkable optical properties has become a driving force, especially for materials science. Tl2In2S3Se [(TlInS2)0.75(TlInSe2)0.25], a fascinating compound, holds great promise for advanced photonic and optoelectronic applications. In the present study, the linear and nonlinear optical properties of Tl2In2S3Se layered single crystals were studied by ellipsometry measurements. The variation of refractive index, extinction coefficient, absorption coefficient and skin depth with energy were investigated. Applying the derivative analysis technique to the absorption spectrum, indirect bandgap was found as 2.19 eV. The refractive index data was analyzed considering single-effective-oscillator model. The lattice dielectric constant, plasma frequency, carrier density to the effective mass ratio and zero-frequency refractive index were found. Moreover, the change in optical conductivity with energy yielded to determine the direct bandgap as 2.42 eV. The optical parameters of nonlinear refractive index, first- and third-order nonlinear susceptibilities were also reported.
Published by Physica B: Condensed Matter, https://doi.org/10.1016/j.physb.2023.415294, M. Isik, Department of Electrical and Electronics Engineering, Atilim University, 06836 Ankara, Turkey, I. Guler, Physics, Inter-Curricular Courses Department, Çankaya University, 06530 Ankara, Turkey, N.M. Gasanly, Department of Physics, Middle East Technical University, 06800, Ankara, Turkey, Virtual International Scientific Research Centre, Baku State University, 1148 Baku, Azerbaijan.
Single crystal, Ellipsometry, Optical constants, Optoelectronic applications