PHONON DYNAMICS AND OPTICAL PROPERTIES OF WURTZITE CdS

DOI: 10.18173/2354-1059.2025-0006

Tóm tắt

This study provides a comprehensive investigation of the structural, vibrational, optical, and thermodynamic properties of wurtzite cadmium sulfide (CdS) using computational methods. Using density functional theory (DFT) and phonon analysis, we reveal stable phonon dispersion with distinct acoustic and optical modes. The phonon density of states (PDOS) highlights the contributions of cadmium and sulfur sublattices, with key modes identified at 34.7 cm⁻¹, 124.4 cm⁻¹, 273 cm⁻¹, and 305.5 cm⁻¹. Optical analysis shows that CdS is transparent below 3.5 eV, exhibiting a maximum refractive index of 2.96 at 3.05 eV, and strong absorption at 7.76 eV (with an extinction coefficient of 1.88). Thermodynamic analysis indicates decreasing entropy and Gibbs free energy with rising temperature. The vibrational zero-point energy (ZPE) is calculated to be 0.124 eV, which is consistent across different calculation methods. These results provide valuable insights into the fundamental properties of CdS for its use in optoelectronic applications.