Abstract Structural, elastic and optoelectronic features of BexZn1−xS, BexZn1−xSe and BexZn1−xTe alloys are computed employing DFT based FP-LAPW approach. Structural features with WC-GGA functional show that lattice constant decrease and… Click to show full abstract
Abstract Structural, elastic and optoelectronic features of BexZn1−xS, BexZn1−xSe and BexZn1−xTe alloys are computed employing DFT based FP-LAPW approach. Structural features with WC-GGA functional show that lattice constant decrease and bulk modulus increase nonlinearly with increase in Be-concentration in each alloy system. The elastic constants C 11 and C 44 for cubic specimens increase, while C 12 decrease with increase in Be-concentration in each system. Elastically anisotropic specimens at x = 0.0 and 0.25 are ductile, while at x = 0.50, 0.75 and 1.0 are brittle in nature. The electronic properties, computed with mBJ, EV-GGA and PBE-GGA functional, predict each ternary sample as a direct band gap (Γ-Γ) semiconductor. Band gap increases nonlinearly with Be-concentration in each system. Chemical bonding between beryllium and chalcogen are ionic and between zinc and chalcogen are covalent in nature. In optical transitions, chalcogen-p in valence band as initial states and Be-3s, 2p as well as Zn-5s states in conduction band as final states play the leading role. Nature of variation of each of the e 1 ( 0 ) , n ( 0 ) and R ( 0 ) with Be-concentration x is opposite, while critical point in each of the e 2 ( ω ) k ( ω ) , σ ( ω ) and α ( ω ) spectra with Be-concentration x is similar to the nature of variation of band gap with Be-concentration in each alloy system.
               
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