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Title: Electronic- and band-structure evolution in low-doped (Ga,Mn)As

Modulation photoreflectance spectroscopy and Raman spectroscopy have been applied to study the electronic- and band-structure evolution in (Ga,Mn)As epitaxial layers with increasing Mn doping in the range of low Mn content, up to 1.2%. Structural and magnetic properties of the layers were characterized with high-resolution X-ray diffractometry and SQUID magnetometery, respectively. The revealed results of decrease in the band-gap-transition energy with increasing Mn content in very low-doped (Ga,Mn)As layers with n-type conductivity are interpreted as a result of merging the Mn-related impurity band with the host GaAs valence band. On the other hand, an increase in the band-gap-transition energy with increasing Mn content in (Ga,Mn)As layers with higher Mn content and p-type conductivity indicates the Moss-Burstein shift of the absorption edge due to the Fermi level location within the valence band, determined by the free-hole concentration. The experimental results are consistent with the valence-band origin of mobile holes mediating ferromagnetic ordering in the (Ga,Mn)As diluted ferromagnetic semiconductor.
Authors:
; ;  [1] ;  [2] ;  [3] ;  [1] ;  [4] ; ; ;  [2]
  1. Institute of Physics, UMCS, Pl. Marii Curie-Skłodowskiej 1, 20-031 Lublin (Poland)
  2. Institute of Physics, Polish Academy of Sciences, 02-668 Warszawa (Poland)
  3. (Sweden)
  4. (United States)
Publication Date:
OSTI Identifier:
22218247
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 5; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CONCENTRATION RATIO; DOPED MATERIALS; FERMI LEVEL; FERROMAGNETIC MATERIALS; GALLIUM ARSENIDES; LAYERS; MAGNETIC PROPERTIES; MOLECULAR BEAM EPITAXY; RAMAN SPECTROSCOPY; SEMICONDUCTOR MATERIALS; X-RAY DIFFRACTION