Investigating the Optoelectronic and Thermoelectric Properties of CdTe Systems in Different Phases: A First-Principles Study

Abstract

CdTe is a potential material for making efficient and stable solar cells. The present study aimed to systematically investigate the electronic, optical, and thermoelectric properties of different structural phases of CdTe using density functional theory. The electronic properties were calculated using the modified Becke−Johnson potential with the local density approximation (LDA) correlation. The band structure profiles showed a direct band at the Γ-point for α-cubic, β-hexagonal, γ-orthorhombic, and an indirect band type for the δ-trigonal phase from the A-point at valence band maximum to the Γ-point at conduction band minimum. Hybridization between Te-p and Cd-s bands in the main valence region was observed in the partial density of states plots for all the studied phases. The real component static values of the dielectric function showed a slight decrease with increasing photonic energy after an initial small increase. The intensity of the imaginary component increased above the threshold energy for each phase, with the δ-phase showing a higher reflectivity spectrum than the other phases due to its intense peaks, making it ideal for protecting against high energy radiations. The results indicated that our computed band gaps and refractive index n(ω) were inversely related. The thermoelectric parameters calculated for these phases suggest that they have potential to be used in thermoelectric devices.

A first-principles study of the electronic, optical, and transport properties of novel transition-metal dichalcogenides

“…Stable materials feature a smooth and well-behaved phonon dispersion plot with no negative frequencies or imaginary modes. 37,38 The CASTEP package, 39 which also operates within the context of DFT, is used for obtaining the phonon dispersion plots of the materials under investigation as displayed in Fig. 2(a)–(c).…”

Cu-based novel transition-metals chalcogenides for advanced optoelectronic and thermoelectric devices: first-principles study

“…The phonon dispersion plot of stable materials is smooth and well-behaved, with no negative frequencies or imaginary modes. The CASTEP software [49], which also works within the context of DFT, is used to compute the phonon dispersions plots of the materials under research, as shown in figures 4(a), (b). The phonon dispersion calculations predicted and validated the stable nature of the studied materials.…”