Effects of Dielectric Screening Function and Image Charges on Hydrogenic Donor Binding Energy in a Surface Quantum Well

Abarna, R.; Anitha, A.; Arulmozhi, M.

doi:10.21315/jps2017.28.1.6

Cited by 6 publications

(1 citation statement)

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“…They have reported that for Impurity States in a Gallium Arsenide Quantum Dot of Rectangular Cross-Section dimensions of the system in which the length is much larger than the radius we obtain two well-defined peaks, associated with acceptors either at the on-centre position or at the edge position in the low-dimensional system. More recently, Abarna et al [15] have reported the effect of dielectric screening on the binding energy of a hydrogenic donor in a Square Quantum well composed of vacuum/GaAs/GaAlAs, as a function of well width and Aluminum composition. Their results showed that decrease in the size of the well increases the binding energy, reaching a peak value at a particular well width.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Hermanson’s Spatial Dielectric Function on the Density of Impurity States in a Gallium Arsenide Quantum Dot of Rectangular Cross-Section

Machuka¹

2018

IJAMTP

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We have carried out a theoretical study of the effect of Hermanson's spatial dielectric function on the density of impurity states (DOIS) for a shallow hydrogenic donor impurity located in the center of a Gallium Arsenide (GaAs) Quantum Well Dot (QWD) of rectangular cross-section. The density of impurity states (DOIS) of an unscreened (hydrogenic) donor impurity was calculated and compared with that of the screened (non-hydrogenic) donor impurity for the same system. Our calculations were carried out using a trial wave function within the effective mass approximation. Our calculations have been carried out with finite barriers. In this study, we first calculated the ground state binding energies of both hydrogenic and nonhydrogenic donor impurity for different dot sizes. The donor binding energies in the two regimes are then used to compute the DOIS. The results show that for both hydrogenic and non-hydrogenic donor impurities, the DOIS sharply rises to a peak, and then decreases almost exponentially with increase in binding energy. The results also show that the DOIS obtained for the nonhydrogenic donor impurities is markedly enhanced over that for purely hydrogenic donor impurities in which a dielectric constant is employed in the potential. In fact, the enhanced DOIS is observed throughout the range of values for binding energy considered. To a good extend there is good agreement between our results and those reported in the literature. It is therefore, important that the effect of the spatial dielectric function should be considered when designing optoelectronic devices.

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Section: Introductionmentioning

confidence: 99%