Fundamental physical properties of some ternary calcopyrite semiconductors compounds calculations based on density functional theory

Inthisworkthestructural,electronic,mechanical,termodynamicandopticalproperties of ternarysemiconductorcompoundsCuAlX2(X =S, Se, Te), ZnSnX2 (X=Sb, As, P), CdSnX2 (X=As,P) andCdGeAs2wereinvestigatedusingfirstprinciplesplane-wavepseudopotentialmethodwithinlocaldensityapproximation (LDA). Energy versuse volume of chalcopyrite(BCT) andcubic- (B1) structures, enthalpy-pressurecurvesandtransitionpressuresweredetermined. The basicphysicalparameters, such as thelatticeconstant, bulk modulus, seconder?orderelastic constants, microhardness, Zener anisotropy factor,Poisson?s ratio, Young?s modulus, isotropic shearmodulusandformationenergy of BCT compoundswerepresented.Bandstructuresanddensity of stateswerecalculated. ChargedensityandMullikenpopulationanalyseswerecarriedoutunderstandthebondingcharacter in theBCT structure of compounds. The thermodynamical properties of the consideredsemiconductor are obtainedthrough the quasi-harmonic Debye model. In order to gain further information, bulk modulus, thermal expansion coefficient, heatcapacity, enthalpy, Debye temperature and Grüneisenparameter were also evaluated over a pressure rangeof 0 - 80GPa and a wide temperature rangeof 0-1000 K.Wehaveanalysedthebasicopticalpropertiessuch as,dielectricfunction, refractiveindex, extinctioncoefficient, theabsorptioncoefficient,opticalreflectivityandelectronenergylossspectrumfor in theenergyrange 0-25eV.Theobtainedresultsare in goodagreementwiththeavailableexperimentalandothertheoreticalvalues.The results showed that the used methods gave the accurate results properties ofcompounds.Key Words : Ab initio method, band structure, elastic properties