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Doping of low-temperature GaAs and GaMnAs with carbon

Authors :
Georg Schmidt
C. Rüster
Rafal Jakiela
Karl Brunner
G. M. Schott
Laurens W. Molenkamp
G. Karczewski
Adam Barcz
Maciej Sawicki
C. Gould
Source :
Applied Physics Letters. 85:4678-4680
Publication Year :
2004
Publisher :
AIP Publishing, 2004.

Abstract

The incorporation of carbon in low-temperature (LT) GaAs and GaMnAs layers deposited by molecular-beam epitaxy under various growth conditions has been investigated. The lattice parameter depends on Mn content, C content, and the growth conditions which strongly affect Mn, C, and point defect incorporation. We found optimum growth conditions (Tsub=270°C, the beam equivalent pressure ratio is 5, growth rate is 0.1nm∕s) at which high-quality GaMnAs layers with moderate Mn content as well as LT-GaAs layers were deposited, which were efficiently p-doped by carbon. LT GaAs:C revealed the same electrical activation of carbon of about 50% at a high doping level p=5×1019cm−3 as observed in high-temperature GaAs:C. The Curie temperature as well as the saturation magnetization of GaMnAs decreases with C doping. This suggests a reduced amount of Mn contributing to the ferromagnetic phase in GaMnAs:C.

Details

ISSN :
10773118 and 00036951
Volume :
85
Database :
OpenAIRE
Journal :
Applied Physics Letters
Accession number :
edsair.doi...........bfb284413266a299d0def02c99cc7bbf
Full Text :
https://doi.org/10.1063/1.1819522