LAUSR

Abstract CdS in its various crystal structures, has been intensively studied both theoretically and experimentally for their extensive industrial application. A Self-consistent calculation within Density Functional Theory (DFT) using norm-conserving pseudopotential plane wave and the precise hybrid functional HSE06. The stability, elastic, mechanical, electronic, and optical properties of C d S O 4 , h - C d S a n d c - C d S are theoretically investigated. Besides, structural and the optical properties of h - C d S thin films were experimentally studied by growing h - C d S thin films using chemical bath deposition (CBD) technique which is well suited for the manufacture of film solar cells. A study of the behavior of the stability and elastic characteristics under hydrostatic pressure is also presented. Band structure analysis using HSE06 and the absorption surface show that C d S O 4 a n d c - C d S hold indirect bandgap while h - C d S is direct bandgap semiconductors. The structures are most stable at the computed relaxed lattice parameter a = b = 4.250 A o , c = 6.667 A o for C d S O 4 , a = b = 4.122 A o , c = 6.660 A o for and h - C d S and a = b = c = 3.804 A o for c - C d S . The Pressure dependence of cubic perovskite elastic moduli, bulk modulus B, shear modulus/constant ( G , C s ) , Young’s modulus E, the Poisson’s ratio σ , Vickers hardness H v , Lame’s constants ( λ , μ ), Cauchy pressure C 12 - C 44 , the Anisotropy factor A , Kleinman parameter ζ , and the P-wave modulus P w , elastic wave velocities v , Debye temperature θ D is presented. The optical properties, both the static refractive index and dielectric constant are found to be related proportionally to the direct bandgaps. The refractive index, extinction coefficient, complex dielectric function, energy loss function, optical conductivity, reflectivity and absorption coefficient for 0 – 40 e V incident photon energies is presented.