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arXiv · 1305.4056

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

O. Yastrubchak·J. Sadowski·H. Krzyzanowska·L. Gluba·J. Zuk·J. Z. Domagala·T. Andrearczyk·T. Wosinski
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Abstract

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 mediated ferromagnetic ordering in the (Ga,Mn)As diluted ferromagnetic semiconductor.

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O. Yastrubchak, J. Sadowski, H. Krzyzanowska, L. Gluba, J. Zuk, J. Z. Domagala, T. Andrearczyk, T. Wosinski. 2013-05-17. Electronic- and band-structure evolution in low-doped (Ga,Mn)As. https://doi.org/10.1063/1.4817420

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