II-VI compound semiconductors are characterized by a large energetic band gap. Among these compounds we found the chalcogenides: beryllium telluride (BeTe) and cadmium telluride (CdTe). BeTe are excellent materials for optoelectronic properties [1] and P-type doping and light emitting diodes (LEDs) [2]. On the other hand, CdTe are important materials in solar cells [3]. Using the Empirical Pseudopotential Method (EPM) within the Virtual Crystal Approximation (VCA) we study the electronic band structure, optical and dielectric properties of BexCd1-xTe alloys in the range (0 ≤ x ≤ 1). The diatomic chalcogenides BeTe and CdTe semiconductors crystallize in cubic zincblende structure. Our results show that the band gap progressively increases with increasing Be concentrations in the BexCd1-xTe alloys. Through our results, we found that the gap energy of BexCd1-xTe is direct in the range from 0 to 0.9 and indirect in the range from 0.9 to 1, due to the fact of the direct gap CdTe (Γ-Γ) and the indirect ones Gap BeTe (Γ-X ). The band gap (Γ-Γ) and (Γ-X) varies non-linearly with increasing beryllium concentration in BexCd1-xTe alloys. We were able to calculate the high-frequency dielectric constant and the static dielectric constant by calculating the optical properties, specifically the refractive index, of six different models. These results corresponded to the experimental values.
Keywords: II-VI compound semiconductors, EPM, BexCd1-xTe, optoelectronic properties, beryllium telluride.
Citation
Khadidja Sassoui ,
FADILA Mezrag ,
,(2022), Influence of Be concentrations on the electronic, optical and dielectric properties of CdTe compound chalcogenide: empirical pseudopotential method (EPM) approach.,1st NATIONAL ONLINE CONFERENCE IN MATERIALS PHYSICS. CNLPM’22 9 Juin 2022, Eltarf, ALGERIA,Eltarf, ALGERIA
