  We report on the spin-polarized electron injection through an
Fe(100)/InAs(100) junction. The circularly polarized electroluminescence of
injected electrons from epitaxially grown Fe thin film into InAs(100) in an
external magnetic field is measured to investigate the spin injection
efficiency. The obtained polarization of the electroluminescence is seen to
increase up to about -12 % at the temperature of 6.5 K and the external
magnetic field of 10 T. This result suggests that the efficient spin injection
is possible through the ferromagnetic metal/semiconductor (FM/SC) interface
without a tunneling barrier despite the contradictory arguments based on
conductivity mismatch at the FM/SC interface.
