FERMI LEVEL POSITION IN GaMnAs -- A THERMOELECTRIC STUDY
V. Osinniya, A. Jędrzejczaka, M. Arciszewskaa, W. Dobrowolskia, T. Storya and J. Sadowskia,b
aInstitute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland
bMAX-lab, Lund University, 22100 Lund, Sweden
Full Text PDF
Thermoelectric power was studied in the temperature range 100<=T<= 300 K in 0.3 -- 1μm thick ferromagnetic Ga1-xMnxAs epitaxial layers (0.015<=x<=0.06) in order to determine Fermi energy EF and carrier concentration p. For 0.015<=x<=0.05, at T=273K we find EF=275±50 meV and p=(2.5±0.5)×1020cm-3 (approximately Mn content independent). For x= 0.06, the Fermi energy decreases by about 100meV with the corresponding reduction of hole concentration to p=1.2×1020cm-3. At T=120K, these parameters vary between EF=380meV and p=3.5×1020cm-3 for x=0.015 to EF=110meV and p=5×1019cm-3 for x=0.06.
DOI: 10.12693/APhysPolA.100.327
PACS numbers: 75.20.Ck, 75.30.Et, 73.50.--h