Electrical spin injection from an n-type ferromagnetic semiconductor into a III-V device heterostructure.
The use of carrier spin in semiconductors is a promising route towards new device functionality and performance. Ferromagnetic semiconductors (FMSs) are promising materials in this effort. An n-type FMS that can be epitaxially grown on a common device substrate is especially attractive. Here, we report electrical injection of spin-polarized electrons from an n-type FMS, CdCr(2)Se(4), into an AlGaAs/GaAs-based light-emitting diode structure. An analysis of the electroluminescence polarization based on quantum selection rules provides a direct measure of the sign and magnitude of the injected electron spin polarization. The sign reflects minority rather than majority spin injection, consistent with our density-functional-theory calculations of the CdCr(2)Se(4) conduction-band edge. This approach confirms the exchange-split band structure and spin-polarized carrier population of an FMS, and demonstrates a litmus test for these FMS hallmarks that discriminates against spurious contributions from magnetic precipitates.
Kioseoglou
George
G
Materials Science and Technology Division, Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375, USA.
Hanbicki
Aubrey T
AT
Sullivan
James M
JM
van 't Erve
Olaf M J
OM
Li
Connie H
CH
Erwin
Steven C
SC
Mallory
Robert
R
Yasar
Mesut
M
Petrou
Athos
A
Jonker
Berend T
BT
D005290:Ferric Compounds; D008280:Magnetics; D012666:Semiconductors
D005290:Ferric Compounds