Electronic band-edge structure, effective masses, and optical absorption of Si1-xGe x using an extended FPLAPW/VCA/LDA+U computational method

AUTOR(ES)

Persson, Clas, Nur, Omer, Willander, Magnus, Silva, Erasmo A. de Andrada e, Silva, Antonio Ferreira da

FONTE

Brazilian Journal of Physics

DATA DE PUBLICAÇÃO

2006-06

RESUMO

Electronic band-edge structure and optical properties of Si1-xGe x are investigated theoretically emloying a full-potential linearized augmented plane wave (FPLAPW) method. The exchange-correlation potential in the local density approximation (LDA) is corrected by an on-site Coulomb potential (i.e., within the LDA+U SIC approach) acting asymmetrically on the atomic-like orbitals in the muffin-tin spheres. The electronic structure of the Si1-xGe x is calculated self-consistently, assuming a Td symmetrized Hamiltonian and a linear behavior of the valence-band eigenfunctions for Si, SiGe, and Ge with respect to Ge composition x, assuming randomly alloyed crystal structure. i.e., a "virtual-crystal like" approximation (VCA). We show that this approach yields accurate band-gap energies, effective masses, dielectric function, and optical properties of Si1-xGe x. We perform absorption measurements showing the band-gap energy for x < 0.25.

Documentos Relacionados

• Electric-field effects on the band-edge states of GaAs/AlAs coupled quantum wells
• Improved electronic structure and optical properties of sp-hybridized semiconductors using LDA+U SIC
• RBS-study of Ge xSi1-x Compounds Formed by Variable Dose Ge Implantation into Si Wafers
• Band Structure, Charge Distribution and Optical Properties of AlPxSb1-x Ternary Semiconductor Alloys
• Espectroscopia de impedância e microestrutura de vitrocerâmicas Li1+x[Al xGe2-x(PO4) 3] condutoras por íons lítio