Influence of donor-triad molecules on the optical properties of semiconductors

Impurity cluster effects in high‐ and low‐doping semiconductor materials

“…The first attempt to explain such lowenergy peak as arising from donor-cluster transitions were carried out by the Heitler-London approximation [14] and by Golka and Piela [15], who used a Hartree-Fock method [5]. However, these works did not explain the low-energy [3,4] have improved the calculations through the dielectric function of the triad molecule using the self-consistent field (SCF) model obtaining results close to experimental findings. We have investigated a donor-triad-cluster model, employing an ab initio multi-configurational self-consistent field (MCSCF) approach to electronic structure determination.…”

“…For doped semiconductors, the effective Bohr radius a à D ¼ a D =ðE à D  eÞ is obtained from the experimental values of the ionization energy E à D and the low-frequency dielectric constant: e(Si) ¼ 11.7, e(GaAs) ¼ 12.4, e(GaN) ¼ 10.0, and e(4HASiC) ¼ 9.85. The dielectric function e(x) ¼ e 1 (x) þ ie 2 (x) describes the optical response of the material, and it is directly related to the absorption a(x) ¼ ÀImhhG(x,R)ii/p, where hh…ii/p, means average disorder of the Green's function propagator [3,4,16]. For the ground-state energies,…”

“…P(R) is the triad distribution function at separation R (see Refs. [3,4,14,16]). The imaginary part e 2 (x) of the dielectric function is obtained from…”

“…The figure for GaAs material includes both the SCF [3,4] and MCSCF model calculations applied to doped with Si. Pe 2 stands for the peak position.…”

“…The MCSCF calculation presents a sharper peak around the experimental results with less dispersion compared to the corresponding SCF result [3,4]. According to Eq.…”