High magnetic field transport and photoluminescence in doped InGaAs/InP superlattices

Lattice-matched InP/InxGa1-xAs short period superlattices (x = 0.53) delta- doped with Si in the middle of the InP barriers were studied. The samples h ad a high carrier concentration which filled two minibands. In addition to a peak associated with the electrons from the second miniband, E2, the Shub nikov-de Haas spectra showed a well resolved doublet structure that is assi gned to El electrons of superlattice wave vectors k(z) = 0 and k(z) = pi/d. From the lineshape of the Shubnikov-de Haas oscillations, an El quantum mo bility of 970 cm(2)/Vs was deduced, which represents an increase of about 4 0% over the value for periodically delta-doped semiconductors. The photolum inescence exhibits a band at photon energies higher than the InGaAs bandgap and whose FWHM approximates the Fermi energy of the confined carriers. Thu s the photoluminescence observed is consistent with the recombination of el ectrons confined by the superlattice potential and photoexcited holes.