Central-cell corrections and shallow donor states in strong magnetic fields

Abstract

Ionization energies and the central-cell corrections have been calculated for a few shallow donors in Si, GaP, and GaAs. We have assumed a short range potential with two parameters for the strength and the range for each donor, representing the central-cell effects. These parameters are fixed using the experimentally available ionization energies for each donor in a semiconductor. In the presence of a magnetic field the donor ionization energies are estimated using a variational procedure. Our results show that the ionization energies and the central-cell corrections increase with magnetic field. Our results are compared for GaAs with the recent work by Heron et al. [R. J. Heron, R. A. Lewis, P. E. Simmonds, R. P. Starret, A. V. Skougarevsky, R. G. Clark, and C. R. Stanley, J. Appl. Phys. 85, 893 (1999)].

Modification to the central-cell correction of germanium acceptors

“…In addition, the potential (6) also reproduces an increase of the chemical shift at low fields (B < 10 T) that perfectly matches the behavior reported in Ref. 8.…”

“…In this work, we address the dependence of the chemical shift as a function of magnetic field, which acts as an additional localization factor for the acceptor wave functions. Previously, the chemical shift for donors in GaAs as a function of magnetic field was studied experimentally by Heron et al 7 and theoretically by Jayam and Navaneethakrishnan, 8 who also use the potential (1); however, the magnetic field was limited to 10 T. In the present work, we apply high magnetic fields up to 50 T and argue that a new, alternating-sign, central-cell correction for germanium acceptors has to be used.…”

Binding Energy of Exciton in Quantum Dots with the Central-cell Correction Depending on the Dot Sizes

“…Similarly, the dot size can be changed by changing γ. In other words, the center-cell effect can be described by changing the dot size R. [11] and our result, respectively. The dots are experimental result [1].…”

“…1. The dashed line is the spherical confinement potential model result [11], the solid line is our result and the dots are experiment result [1].…”

“…Recently some authors [11,12] have studied the central-cell corrections for donors in semiconductors as analogy problem of excitons. Beyond the effective mass theory, instead of the Coulombic potential they have assumed a short range potential with two parameters for the strength and the range for donors, representing the central-cell effects.…”