SPIN-POLARIZED ELECTRONS FROM INXGA1-XAS THIN-FILMS

Using optical spin orientation photoelectrons with spin polarization above 50% have been extracted from strained III-V semiconductors. The new sources consist of an epitaxial overlayer having a smaller energy gap and a slightly larger lattice constant than the substrate material. The tensile stress along the surface normal lifts the orbital degeneracy of the levels at the valence band maximum such that the polarization is enhanced compared to the unstrained cubic material.