Effects of Defects and Local Thickness Modulation on Spin-Polarization in Photocathodes based on GaAs/GaAsP Strained Superlattices

摘要

The spin polarization of electrons from the GaAs/GaAsP superlattice on GaAs is higher than that from the same superlattice on GaP. TEM observation revealed that in the superlattice on GaAs stacking faults were the main defects but in the superlattice on GaP local thickness modulation of superlattice layers was prominent. Stacking faults and thickness modulation have different effects on the spin-polarization.