[SLAC Pubs and Reports]
Comparison of ALINGAAS/GAAS Superlattice Photocathodes Having Low Conduction Band Offset
The main advantage of superlattice (SL) structures as spin polarized electron emitters is
the ability to provide a large splitting between the heavy hole (HH) and light hole (LH)
valence bands (VB) over a large active thickness compared to single strained layers. Two
important depolarization mechanisms in these structures are the scattering effects during
the transit of the electrons in the active region and the depolarization that takes place in
the band bending region (BBR) near the surface. In this paper, we systematically study
the effects of the electron mobility and transit time by using an InAlGaAs/GaAs SL with
a flat conduction band (CB). Initial results by the SPTU-SLAC collaboration using such
structures grown by the Ioffe Institute showed polarization and quantum yield (QE) of
92% and 0.2% respectively. We report measurements using similar structures grown by
SVT Associates. The results (polarization up to 90%) are also compared with simulations.
Not available for this document.
Full bibliographic data for this document, including its complete author list,
is (or soon will be) available from SLAC's
Please report problems with this file to
The SLAC preprint inventory is provided by the
SLAC Technical Publications Department.
Page generated 31 Mar 2006 @ 08:56 PST by htmlme.pl