| 摘要 |
PURPOSE:To decrease the effective mass of holes and to increase the mobility of the holes, by decreasing the mutual action between hole bands in quantum wells by applying strain. CONSTITUTION:A superlattice comprising two kinds of semiconductors is formed. At this time, the mutual actions between hole bands in quantum wells are decreased by applying stress. When compression strain is applied by +1%, the discontinuous quantity of a valence band is increased by about 140 meV in GaAsxP(1-x) and GaAs, in which deformation potential is negative, in comparison with the case strain is absent. As a result, the mutual actions between the heavy holes in the valence band of a GaAs layer is reduced. The mass of the holes in the vicinity of a Fermi surface is largely reduced. The mutual actions between the heavy hole bands in the valence band are similarly reduced by narrowing the width of the quantum well. Thus the effective mass of the holes is decreased and the mobility of the holes is increased.
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