Energy resolved spin-polarised electron photoemission from strained GaAs/GaAsP heterostructure

High resolution energy distribution curves (EDC) and a polarisation versus energy distribution curves (PEDC) of the electrons, photoemitted from strai ned GaAs/GaAsP layers are experimentally studied. The basic structures of t he spectra are found to vary with temperature and illuminating wavelength. The ageing of the activation layer changes the EDC shape as well. Neverthel ess, in the vicinity of the photoexcitation threshold the polarisation does not vary across the energy distribution both at room and 120 K temperature s of the cathode, which means that no depolarisation occurs during energy r elaxation in the band bending region. The electron energy distribution is i nterpreted in terms of the electron energy relaxation in the band tail stat es of the quantum well formed by the band-bending region. (C) 2000 Publishe d by Elsevier Science Ltd. All rights reserved.