First‐principles calculations of structural, electronic, optical, and thermoelectric properties of ternary d ‐metal sulfides Sc ₂ CdS ₄ and Y ₂ CdS ₄ compounds

Abstract

Direct energy bandgap materials are crucial for efficient optoelectronics devices. Therefore, investigating new direct gap materials is important. In the present work, two novel d-metal sulfides Sc 2 CdS 4 and Y 2 CdS 4 compounds are investigated by using the all-electron full-potential linearized augmented plane-wave method. The energy optimization predicts lattice constants 10.85 and 11.31 Ǻ for Sc 2 CdS 4 and Y 2 CdS 4 , respectively. Both the compounds show semiconducting nature and direct bandgap with a value of 1.886 eV for Sc 2 CdS 4 and 2.209 eV for Y 2 CdS 4 . Strong hybridization between S-p and Sc/Y-d orbitals is present among valence and conduction bands, which is beneficial to electrical transport. Key optical parameters are calculated. The static value of the reflectivity R(0) and refractive index n(0) varies inversely with the energy bandgap (E g ). Both the compounds Sc 2 CdS 4 and Y 2 CdS 4 are P-type thermoelectric materials because the holes carriers dominate the electronic transport. Both the compounds reveal figure of merit of about 0.5. Appropriate direct energy gap and figure of merit indicate the possible applications of these compounds for energy conversion devices.

GGA and GGA + U Study of ThMn2Si2 and ThMn2Ge2 Compounds in a Body-Centered Tetragonal Ferromagnetic Phase

“…Even the closer states allowed for simple electron mobility, which over time affected the materials’ conductivity. Moreover, the compounds adopted the tetragonal ThCr 2 Si 2 -type structure with three-dimensional electron and hole-like multiband Fermi surfaces (FSs), as appeared in the majority of the same types [ 46 , 47 ] and other types [ 41 , 48 , 49 ] of compounds that were related to the phonon-mediated types that were currently under electron-phonon mediated superconductivity, according to a few other research studies that calculated Fermi surfaces (FSs). Due to the crossing and overlapping of bands across the Fermi level of energy, as well as the absence of a gap in both spin states when utilizing two separate (PBE–GGA and GGA + U) approximations, the thorium compound ThMn 2 X 2 band structures generally described the full metallic nature.…”

Structural, Thermoelectric, Electronic, and Magnetic Properties of Pristine Intermetallic Rare-Earth-Based XMn2Si2 (X=Dy, Er) Compounds

“…Moreover, its thermoelectric properties have now been studied using the semi-classical ECS Journal of Solid State Science and Technology, 2023 12 043012 Boltzmann transport theory, which is performed in the Boltztrap program. [58][59][60]…”

“…Thermoelectric Properties.-BoltzTraP is the algorithm used to compute thermoelectric parameters based on semi-classical Boltzmann theory. [58][59][60] For thermoelectric materials, particularly those used in detectors and cooling equipment, low and high temperature refrigeration, thermal energy provides a source for the creation of electrical energy. A material is said to be more efficient if it contributes less thermal conductivity and higher electrical conductivity and Seebeck coefficient.…”

Electronic structure, magnetic, and thermoelectric properties of BaMn2As2 compound: a first-principles study

“…To figure out the electronic nature of BaMn 2 As 2 , the electronic structure is calculated by modified Becke-Johnson exchange potential (mBJ-GGA) [39,49,50]. The electronic band-structure with DOS plot is depicted in figures 4(a), (b).…”