First principles calculations of the structural and electronic properties of AlAs, InAs and their alloy AlxIn1–xAs have been performed using the full-potential linear muffin-tin orbital (FP-LMTO) [1] method within de...First principles calculations of the structural and electronic properties of AlAs, InAs and their alloy AlxIn1–xAs have been performed using the full-potential linear muffin-tin orbital (FP-LMTO) [1] method within density functional theory (DFT) [2,3]. We used the local density approximation (LDA) [4] within the generalized gradient correction (GGA) [5] to calculate the electronic structure at equilibrium volume. The effect of composition on lattice constants, bulk modulus and band gap were investigated. Deviations of the lattice constants from Vegard’s law and the bulk modulus were observed for this alloy. The microscopic origins of the gap bowing were explained by using the approach of Zunger and co-workers [6-9].展开更多
The structural and the electronic properties of the ternary SrxCa1-xS, BaxCa1-xS and BaxSr1-xS alloys have been calculated using the full-potential linear muffin-tin-orbital (FP-LMTO) method based on density functiona...The structural and the electronic properties of the ternary SrxCa1-xS, BaxCa1-xS and BaxSr1-xS alloys have been calculated using the full-potential linear muffin-tin-orbital (FP-LMTO) method based on density functional theory, within both local density approximation (LDA) and generalized gradient approximation (GGA). The calculated equilibrium lattice constants and bulk modulus are compared with previous results. The concentration dependence of the electronic band structure and the direct and indirect band gaps are investigated. Using the approach of Zunger and co-workers, the microscopic origins of the band gap bowing are investigated also. A reason is found from the comparison of our results with other theoretical calculations.展开更多
We perform self-consistent ab-initio calculations to study the structural and electronic properties of zinc blende ZnS, ZnO and their alloy. The full-potential muffin-tin orbitals (FP-LMTO) method was employed within ...We perform self-consistent ab-initio calculations to study the structural and electronic properties of zinc blende ZnS, ZnO and their alloy. The full-potential muffin-tin orbitals (FP-LMTO) method was employed within density functional theory (DFT) based on local density Approximation (LDA), and generalized gradient approximation (GGA). We analyze composition effect on lattice constants, bulk modulus, band gap and effective mass of the electron. Using the approach of Zunger and coworkers, the microscopic origins of band gap bowing have been detailed and explained. Discussions will be given in comparison with results obtained with other available theoretical and experimental results.展开更多
The present work performs self-consistent ab initio full-potential linear muffin-tin orbital (FP-LMTO) method to study the structural and electronic properties of the ternary ZnxCd1-xSe alloy, based on density functio...The present work performs self-consistent ab initio full-potential linear muffin-tin orbital (FP-LMTO) method to study the structural and electronic properties of the ternary ZnxCd1-xSe alloy, based on density functional theory (DFT). In this approach, both the local density approximation (LDA) and the generalized gradient approximation (GGA) were used for the exchange-correlation potential calculation. The ground-state properties are determined for the bulk materials CdSe, ZnSe and their alloy in cubic phase. In particular, the lattice constant, bulk modulus, electronic band structures and effective mass. We mainly showed deviation of the lattice parameter and bulk modulus from Vegard’s law of our alloys. We also presented the microscopic origins of the gap bowing using the approach of Zunger et al. The results are compared with other theoretical calculations and experimental data and are in reasonable agreement.展开更多
The optical response of subwavelength silver nanowires arranged periodically on silica has been analyzed numerically by the differential method improved by the S matrix algorithm. Our results improve the capacity of t...The optical response of subwavelength silver nanowires arranged periodically on silica has been analyzed numerically by the differential method improved by the S matrix algorithm. Our results improve the capacity of this rigorous method to give a description of various phenomena occurring in near and far field around the periodic grating. This renders pos- sible to determine the positions of plasmon’s resonance according to the choice of materials used and the geometrical properties. We study the behavior of the diffracted light by the nano-structure in both single nanowire case and grating nanowires case. The influence of the exact grating period and the induced modification of the spacer nanowire depend- ence are then discussed. Moreover, we present mappings of the electromagnetic field located at 50 nm above the nanowires.展开更多
The equilibrium structure and the electronic properties of III-V zinc-blende AlP, InP semiconductors and their alloy have been studied in detail from first-principles calculations. A full-potential linear muffin-tin-o...The equilibrium structure and the electronic properties of III-V zinc-blende AlP, InP semiconductors and their alloy have been studied in detail from first-principles calculations. A full-potential linear muffin-tin-orbital (FP-LMTO) method has been used in conjunction with both the local-density approximation (LDA) and the generalized-gradient approximation (GGA) to investigate the effect of increasing the concentration of aluminum on the structural properties such as the lattice constants and the bulk moduli. Besides, we report the concentration dependence of the electronic band structure, the direct-indirect band gap crossovers and bowing. Using the approach of Zunger and co-workers the microscopic origins of the gap bowing were also explained. A reasonable agreement is found in comparing our results with other theoretical calculations.展开更多
First-principles calculations have been used to study the structural and electronic properties of BaS1–xSex ternary alloy using full-potential muffin-tin orbital’s (FP-LMTO) method within density functional theory (...First-principles calculations have been used to study the structural and electronic properties of BaS1–xSex ternary alloy using full-potential muffin-tin orbital’s (FP-LMTO) method within density functional theory (DFT). In this approach, the local-density approximation (LDA) and generalized gradient approximation (GGA) are used for the exchange-correlation (XC) potential. The effect of composition on lattice parameter, bulk modulus, band gap and effective mass was investigated. The deviations of the lattice constant from Vegard’s law and the bulk modulus from linear concentration depend- ence were observed for BaS1–xSex alloy. The microscopic origins of bowing parameter were explained using approach of Zunger and co-workers. Accordance is found from the comparison of our results with other experimental and theo- retical calculations.展开更多
The structural and electronic properties of the ternary CuxAg1–xI, alloy have been calculated, using the full-potential linear muffin-tin-orbital (FP-LMTO) method based on density functional theory, within both the l...The structural and electronic properties of the ternary CuxAg1–xI, alloy have been calculated, using the full-potential linear muffin-tin-orbital (FP-LMTO) method based on density functional theory, within both the local density approximation and the generalized gradient approximation (GGA). The equilibrium lattice constants and the bulk modulus are compared with previous theoretical calculations. The concentration dependence of the electronic band structure and the direct-indirect band gaps is also investigated. Using the approach of Zunger and co-workers the microscopic origins of the gap bowing were also explained.展开更多
文摘First principles calculations of the structural and electronic properties of AlAs, InAs and their alloy AlxIn1–xAs have been performed using the full-potential linear muffin-tin orbital (FP-LMTO) [1] method within density functional theory (DFT) [2,3]. We used the local density approximation (LDA) [4] within the generalized gradient correction (GGA) [5] to calculate the electronic structure at equilibrium volume. The effect of composition on lattice constants, bulk modulus and band gap were investigated. Deviations of the lattice constants from Vegard’s law and the bulk modulus were observed for this alloy. The microscopic origins of the gap bowing were explained by using the approach of Zunger and co-workers [6-9].
文摘The structural and the electronic properties of the ternary SrxCa1-xS, BaxCa1-xS and BaxSr1-xS alloys have been calculated using the full-potential linear muffin-tin-orbital (FP-LMTO) method based on density functional theory, within both local density approximation (LDA) and generalized gradient approximation (GGA). The calculated equilibrium lattice constants and bulk modulus are compared with previous results. The concentration dependence of the electronic band structure and the direct and indirect band gaps are investigated. Using the approach of Zunger and co-workers, the microscopic origins of the band gap bowing are investigated also. A reason is found from the comparison of our results with other theoretical calculations.
文摘We perform self-consistent ab-initio calculations to study the structural and electronic properties of zinc blende ZnS, ZnO and their alloy. The full-potential muffin-tin orbitals (FP-LMTO) method was employed within density functional theory (DFT) based on local density Approximation (LDA), and generalized gradient approximation (GGA). We analyze composition effect on lattice constants, bulk modulus, band gap and effective mass of the electron. Using the approach of Zunger and coworkers, the microscopic origins of band gap bowing have been detailed and explained. Discussions will be given in comparison with results obtained with other available theoretical and experimental results.
文摘The present work performs self-consistent ab initio full-potential linear muffin-tin orbital (FP-LMTO) method to study the structural and electronic properties of the ternary ZnxCd1-xSe alloy, based on density functional theory (DFT). In this approach, both the local density approximation (LDA) and the generalized gradient approximation (GGA) were used for the exchange-correlation potential calculation. The ground-state properties are determined for the bulk materials CdSe, ZnSe and their alloy in cubic phase. In particular, the lattice constant, bulk modulus, electronic band structures and effective mass. We mainly showed deviation of the lattice parameter and bulk modulus from Vegard’s law of our alloys. We also presented the microscopic origins of the gap bowing using the approach of Zunger et al. The results are compared with other theoretical calculations and experimental data and are in reasonable agreement.
文摘The optical response of subwavelength silver nanowires arranged periodically on silica has been analyzed numerically by the differential method improved by the S matrix algorithm. Our results improve the capacity of this rigorous method to give a description of various phenomena occurring in near and far field around the periodic grating. This renders pos- sible to determine the positions of plasmon’s resonance according to the choice of materials used and the geometrical properties. We study the behavior of the diffracted light by the nano-structure in both single nanowire case and grating nanowires case. The influence of the exact grating period and the induced modification of the spacer nanowire depend- ence are then discussed. Moreover, we present mappings of the electromagnetic field located at 50 nm above the nanowires.
文摘The equilibrium structure and the electronic properties of III-V zinc-blende AlP, InP semiconductors and their alloy have been studied in detail from first-principles calculations. A full-potential linear muffin-tin-orbital (FP-LMTO) method has been used in conjunction with both the local-density approximation (LDA) and the generalized-gradient approximation (GGA) to investigate the effect of increasing the concentration of aluminum on the structural properties such as the lattice constants and the bulk moduli. Besides, we report the concentration dependence of the electronic band structure, the direct-indirect band gap crossovers and bowing. Using the approach of Zunger and co-workers the microscopic origins of the gap bowing were also explained. A reasonable agreement is found in comparing our results with other theoretical calculations.
文摘First-principles calculations have been used to study the structural and electronic properties of BaS1–xSex ternary alloy using full-potential muffin-tin orbital’s (FP-LMTO) method within density functional theory (DFT). In this approach, the local-density approximation (LDA) and generalized gradient approximation (GGA) are used for the exchange-correlation (XC) potential. The effect of composition on lattice parameter, bulk modulus, band gap and effective mass was investigated. The deviations of the lattice constant from Vegard’s law and the bulk modulus from linear concentration depend- ence were observed for BaS1–xSex alloy. The microscopic origins of bowing parameter were explained using approach of Zunger and co-workers. Accordance is found from the comparison of our results with other experimental and theo- retical calculations.
文摘The structural and electronic properties of the ternary CuxAg1–xI, alloy have been calculated, using the full-potential linear muffin-tin-orbital (FP-LMTO) method based on density functional theory, within both the local density approximation and the generalized gradient approximation (GGA). The equilibrium lattice constants and the bulk modulus are compared with previous theoretical calculations. The concentration dependence of the electronic band structure and the direct-indirect band gaps is also investigated. Using the approach of Zunger and co-workers the microscopic origins of the gap bowing were also explained.
