FP-LMTO study of structural, electronic, thermodynamic and optical properties of MgxCd1−x Se alloys

Abstract

Structural, electronic and optical properties of Mg x Cd 1−x Se (0 x 1) are calculated for the first time using density functional theory. Our results show that these properties are strongly dependent on molar fraction of particular componentsx. The bond between Cd and Se is partially covalent and the covalent nature of the bond decreases as the concentration of Mg increases from 0 % to 100 %. It is found that Mg x Cd 1−x Se has a direct band gap in the entire range of x and the band gap of the alloy increases from 0.43 to 2.46 eV with the increase in Mg concentration. Frequency dependent dielectric constants ε 1 (ω), ε 2 (ω) refractive index n(ω) are also calculated and discussed in detail. The peak value of refractive indices shifts to higher energy regions with the increase in Mg. The larger value of the extraordinary refractive index confirms that the material is a positive birefringence crystal. The present comprehensive theoretical study of the optoelectronic properties of the material predicts that it can be effectively used in optoelectronic applications in the wide range of spectra: IR, visible and UV. In addition, we have also predicted the heat capacities (C V ), the entropy (S), the internal energy (U) and the Helmholtz free energy (F) of Mg x Cd 1−x Se ternary alloys.

Mg substitution in zinc selenide: Enhanced optoelectronic and thermoelectric performance

“…The knowledge band structures energy of semiconductors provides valuable information for their potential utility in devices optoelectronics. The The data presented in Table S2 indicate that the values calculated for the MgSe and ZnSe band gaps are closer to the experimental than others calculated [31][32][33][34][35][36][37][38]. The reason behind the use of the FP-LMTO method through the approximation of local density (LDA), effective Perdew and Wang potential [5], and high k-point (1500).…”

“…The data presented in Table S2 indicate that the values calculated for the MgSe and ZnSe band gaps are closer to the experimental than others calculated [31‐38]. The reason behind the use of the FP‐LMTO method through the approximation of local density (LDA), effective Perdew and Wang potential [5], and high k ‐point (1500).…”

Electronic and optical properties of ternary alloys ZnxCd1−xS, ZnxCd1−xSe, ZnSxSe1−x, MgxZn1−xSe

“…A study of the structural, electronic and optical properties of (BeTe/ZnSe) supperlattices has been performed using the full potential linear muffin-tin orbital method (FP-LMTO) [10]. This method has also been used in order to investigate optoelectronic nature of MgCdSe alloys [11]. The electronic and optical properties of ZnS, ZnSe, CdS, CdSe and their alloy ZnCdSSe have been investigated using the empirical pseudopotential method (EPM) [12].…”