Optical characterization and dispersion discussions of the novel thermally evaporated thin a-S50-xGe10CdxTe40 films

In this article, the authors have been interested in synthesizing and studying the novel amorphous thin S50-xGe10CdxTe40 films (SGCT) (0 <= x <= 15 at.%) from their glassy bulk compositions. The authors have deposited thin films on pure, transparent, and well-pre-cleaned glass substrates using the thermal evaporation route under a vacuum approximate to 10(-4) Pa. Both the deposition rate and film thickness are fixed during depositing SGCT-films at 10 nm/s and 750 nm, respectively. Film samples have been characterized via X-ray diffraction, energy-dispersive X-ray spectroscopy, and optical spectrophotometric measurements for reflection and transmission in the 500-2500 nm spectral range. Based on Minkov's envelope method, the reflection spectra are employed to get the thickness, d, and refractive index, n, of films. The n-values have been found to increase from 2.755 to 3.300 as the Cd-percentage increases. The single effective oscillator model is used to get dispersion energies and parameters. The dispersion energy increases from 16.11 to 16.73 eV, while the single effective oscillator energy decreases from 3.23 eV to 2.65 eV. Tauc's and Urbach's energies (E-g and E-e, respectively) have been determined where Eg decreased from 1.60 to 1.31 (eV), while Ee increased from 0.0276 to 0.0644 (eV) as the Cd content was increased.

Automated summary

This article focuses on the synthesis and study of novel amorphous thin S50-xGe10CdxTe40 films, and various characteristics such as refractive index and dispersion energy were obtained through testing. The results show that the refractive index and dispersion energy of the films change as the Cd content increases.