|
Semiconductor Physics, Quantum Electronics & Optoelectronics. 2007. V. 10, N 3. P. 010-016.
Electron energy spectrum in a spherical quantum dot
with smooth confinement
Chernivtsi National University
2, Kotsyubynsky str., 58012 Chernivtsi, Ukraine; e-mail: theorphys@chnu.cv.ua
Abstract. The electron energy spectrum in a quantum dot (QD) with smooth
dependences of the quasiparticle potential energy and the effective mass at the interface
between semiconductor media is calculated in the effective mass approximation. It is
shown that the electron energy corrections due to the tailing of the interface are
nonmonotonous functions of the QD radius, the increasing of which brings to the rapid
increasing of shifts, reaching their maxima, and slowly decreasing for the QDs of big
sizes. The calculations prove that the relative corrections for the different electron energy
levels in a spherical QD are placed closer to each other with increase in the radius. The
growth of the parameter of interface tailing leads to the proportional increase in the
corrections to electron energy spectra. Numerical calculations are performed for
HgS/CdS and GaAs/Al x Ga 1-x As QDs, all dependences being qualitatively similar.
Keywords: quantum dot, smooth confinement, interface, electron energy spectrum.
| ||