Semiconductor device for emitting highly spin-polarized electron beam

Abstract

A semiconductor device for emitting, upon receiving a light energy, a highly spin-polarized electron beam, including a first compound semiconductor layer formed of gallium arsenide phosphide, GaAs.sub.l-x P.sub.x, and having a first lattice constant; a second compound semiconductor layer grown with gallium arsenide, GaAs, on the first compound semiconductor layer, and having a second lattice constant different from the first lattice constant, the second compound semiconductor layer emitting the highly spin-polarized electron beam upon receiving the light energy; and a fraction, x, of the gallium arsenide phosphide GaAs.sub.l-x P.sub.x and a thickness, t, of the second compound semiconductor layer defining a magnitude of mismatch between the first and second lattice constants, such that the magnitude of mismatch provides a residual strain, .epsilon..sub.R, of not less than 2.0.times.10.sup.-3 in the second layer. The fraction x of the gallium arsenide phosphide GaAs.sub.l-x P.sub.x and the thickness t of the second compound semiconductor layer may define the magnitude of mismatch between the first and second lattice constants, such that the magnitude of mismatch provides an energy splitting between a heavy hole band and a light hole band in the second layer so that the energy splitting is greater than a thermal noise energy in the second layer.

Dependencies are inferred from the claim text.