Photoexcitation at the Schottky barrier formed between 5 nm thick Ni80Fe20
films and both n(+)- and p(-)-type GaAs(100) substrates with doping density
in the range 10(23)less than or equal to n(p)less than or equal to 10(25)
m(-3) was investigated using circularly polarized laser light. A helicity-d
ependent photocurrent dependent upon the magnetization configuration of the
film and the Schottky barrier height was detected. The results provide evi
dence of spin-dependent electron transport through the NiFe/GaAs interface
and show that the Schottky barrier height controls the spin-dependent curre
nt passing from the semiconductor to the ferromagnet. (C) 2000 American Ins
titute of Physics. [S0021-8979(00)05608-5].