1 research outputs found
Spin- and energy relaxation of hot electrons at GaAs surfaces
The mechanisms for spin relaxation in semiconductors are reviewed, and the
mechanism prevalent in p-doped semiconductors, namely spin relaxation due to
the electron-hole exchange interaction, is presented in some depth. It is shown
that the solution of Boltzmann-type kinetic equations allows one to obtain
quantitative results for spin relaxation in semiconductors that go beyond the
original Bir-Aronov-Pikus relaxation-rate approximation. Experimental results
using surface sensitive two-photon photoemission techniques show that the spin
relaxation-time of electrons in p-doped GaAs at a semiconductor/metal surface
is several times longer than the corresponding bulk spin relaxation-times. A
theoretical explanation of these results in terms of the reduced density of
holes in the band-bending region at the surface is presented.Comment: 33 pages, 12 figures; earlier submission replaced by corrected and
expanded version; eps figures now included in the tex