First principles study of the structural, optoelectronic and mechanical properties of XLaS2 (X[dbnd]Cu, Zn) for optoelectronic applications.

The exploration of most suitable materials for optoelectronic applications is dire need of the current era of the Science and Technology. Here, we have discussed the structural parameters, optoelectronic and mechanical behavior of XLaS 2 (X Cu, Zn), monoclinic structures, for optoelectronic applications. The calculated lattice parameters for CuLaS 2 are found to be a = 6.551 Å, b = 7.218 Å, c = 6.852 Å with lattice angles α = 90°, β = 98° and γ = 90°, while for ZnLaS 2 these are a = 6.619 Å, b = 7.310 Å, c = 6.926 Å and α = 90°, β = 98° and γ = 90°. In addition, values of the energy band gap calculated for CuLaS 2 and ZnLaS 2 are 1.26 eV and 0.27 eV, respectively which reveal their semiconducting nature. The total density of states (TDOS) and partial density of states (PDOS) are determined using Perdew Burke Ernzerhof generalized gradient approximation (PBE-GGA). Moreover, dielectric function, absorption coefficient, refractive index, optical conductivity, reflectivity and energy loss function are evaluated with 0.5 eV smearing value for seeking their optical behavior. According to Born's criterion, CuLaS 2 is found brittle while ZnLaS 2 as ductile material for different mechanical applications. Moreover, both these materials can hold an anisotropic behavior. Both these materials are found to be good absorber of Ultraviolet rays from the electromagnetic radiations, this unique quality has compelled us to declare them very suitable materials for optoelectronic applications. • The studied compounds belong to semiconductor category. • PBE-GGA functional is used to seek electronic behavior. • Optical absorption is found in the ultraviolet region of electromagnetic waves. • CuLaS 2 is found brittle while ZnLaS 2 as ductile material. [ABSTRACT FROM AUTHOR]