A new candidate for optoelectronic device applications: CoTiX (X: P, As, Sb) half-heusler compounds

Abstract

Some theoretical calculations of CoTiX(X:P, As, Sb) Half-Heusler(HH) compounds in MgAgAs-type structure have been analyzed using density functional theory (DFT). These Half-Heusler compounds are stable mechanically, and CoTiAs are entirely isotropic, whereas CoTiP and CoTiSb are anisotropic. Mechanical properties indicate that they have a ductile nature in all three compounds. In addition, elastic properties are presented in three dimensions (3D) for detailed analysis of Young's modulus, linear compressibility, shear modulus, and Poisson's ratio. Electronically, the investigated compounds are semiconductors with an indirect bandgap. The calculated positive phonon vibration frequencies of these Half-Heusler compounds show their dynamic stability in the cubic MgAgAs phase. Optical parameters such as dielectric function, reflectivity, absorption coefficient, refractive index, loss function, and absorption coefficient are given in IR, visible, and ultraviolet regions according to considerable photon energies. Finally, the effects of pressure and temperature on thermodynamic properties are discussed in detail.