OPTICAL-ABSORPTION SPECTRA ASSOCIATED WITH SHALLOW DONOR IMPURITIES IN GAAS-(GA,AL)AS QUANTUM-WELL WIRES

The optical-absorption spectra associated with transitions between the n = 1 valence subband and the donor-impurity band was calculated for infinite GaAs-(Ga,Al)As cylindrical quantum - well wires of different radii. An absorption edge associated with transitions involving impurities at the center of the well and a peak related with impurities at the edge of the wire were the main features observed. As a result of the higher electronic confinement in quantum-well wires, we found a much wider range of the absorption energy in quantum-well wires as compared to an infinite GaAs-(Ga,Al)As quantum well of width comparable to the well diameter of the wires. © 1990.