Détermination des propriétés structurales, électroniques et optiques du composé dichalcogénure TlInX2 (X=S, Se et Te) :calcul ab-intion

Abstract

The present work explores the structural, electronic and optical properties of the wurtzite TlInX2 (X=S, Se, Te) ternary alloys. The calculations were performed using density functional theory (DFT) within full-potential linearized augmented planes waves (FP-LAPW) method implemented in the Wien2k package. First, the structural properties such as the lattices parameters a and c with bulk modulus B and first pressure derivative B’ are determined from three distinguished approximations PBE-GGA, PW-LAD and WC-GGA. When X is moved at S, Se and Te atoms the lattice a increases and c parameter decreases. Second, the electronic properties like direct and indirect bandgap of TlInS 2 , TlInSe2 and TlInTe 2 are investigated using both PBE-GGA and TB-mBJ approximations. The results shows that the ternary alloys are semiconductors with direct bandgap energy. The gap increases if X moves to S, Se and Te atoms. Third, the optical properties such as real and imaginary parts with the refractive index of the ternary alloys are predicted in this study. The curves of optical properties shift