Band-gap narrowing in Mn-doped GaAs probed by room-temperature photoluminescence
Band-gap narrowing in Mn-doped GaAs probed by room-temperature photoluminescence
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DOI：
10.1103/physrevb.92.224407
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发表时间：
2015-10
影响因子：
3.7
通讯作者：
S. Prucnal;K. Gao;I. Skorupa;L. Rebohle;L. Vines;H. Schmidt;M. Khalid;Y. Wang;E. Weschke;W. Skorupa;J. Grenzer;R. Huebner;M. Helm;S. Zhou
中科院分区：
文献类型：
--
作者：
S. Prucnal;K. Gao;I. Skorupa;L. Rebohle;L. Vines;H. Schmidt;M. Khalid;Y. Wang;E. Weschke;W. Skorupa;J. Grenzer;R. Huebner;M. Helm;S. Zhou
在过去的二十年里，(Ga，Mn)As系统的电子能带结构一直是固体物理学中最感兴趣的问题之一。确定能带结构随锰含量增加的演化规律是理解铁磁性起源的关键。在这里，我们介绍了$\mathrm{G}{\mathrm{a}}_{100%\ensuremath{-}x}\mathrm{M}{\mathrm{n}}_{x}\mathrm{As}$合金的室温光致发光和椭偏测量。随着Mn含量的增加，$\mathrm{G}{\mathrm{a}}_{100%\ensuremath{-}x}\mathrm{M}{\mathrm{n}}_{x}\mathrm{As}$合金禁带发射附近的室温红移证明了价带的上移。结果表明，即使掺入0.02%的锰，也会影响价带边，并且在低至0.6%的掺杂浓度下，价带边就会与杂质带合并。X射线衍射图和高分辨率横截面电子显微镜图像都证实了注入层的完全再结晶和GaMnAs合金的形成。
The electronic band structure of the (Ga,Mn)As system has been one of the most intriguing problems in solid state physics over the past two decades. Determination of the band structure evolution with increasing Mn concentration is a key issue to understand the origin of ferromagnetism. Here, we present room-temperature photoluminescence and ellipsometry measurements of $\mathrm{G}{\mathrm{a}}_{100%\ensuremath{-}x}\mathrm{M}{\mathrm{n}}_{x}\mathrm{As}$ alloy. The upshift of the valence band is proven by the redshift of the room temperature near band-gap emission from the $\mathrm{G}{\mathrm{a}}_{100%\ensuremath{-}x}\mathrm{M}{\mathrm{n}}_{x}\mathrm{As}$ alloy with increasing Mn content. It is shown that even a doping by 0.02% of Mn affects the valence-band edge, and it merges with the impurity band for a Mn concentration as low as 0.6%. Both x-ray diffraction pattern and high-resolution cross-sectional transmission electron microscopy images confirmed full recrystallization of the implanted layer and GaMnAs alloy formation.