Abstract

In semiconductor quantum dots (QDs) with radii of several nanometers, electron-hole eigenstates are energetically discrete because of the quantum confinement effect. On the other hand, quasizero-dimensional electron-hole systems are created in MQW by applying a magnetic field.¹ At a weak magnetic field, the Zeeman splitting is expected to be observed.^2,3 The absorption peak is split into two peaks corresponding to two states with magnetic quantum numbers of ±1. At a strong magnetic field, the Coulomb effect becomes less important than the magnetic-field effect and the Landau levels with equal energy splittings are formed. The formation of the Landau levels gives a blue shift in the absorption spectral, and is expected to eliminate the surface effect in a zero-dimensional system in a strong magnetic field because the parabolic potential due to the magnetic field keeps electron-hole pairs away from the surface. In this paper, we evaluate the magnetic-field effect in CdSSe QDs by measuring the absorption changes when applying a magnetic field.

© 1995 IEEE