Compositional dependence of the exciton reduced mass in GaAs1-xBix (x=0-10%)
Compositional dependence of the exciton reduced mass in GaAs1-xBix (x=0-10%)
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DOI：
10.1103/physrevb.81.235211
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发表时间：
2010-06
影响因子：
3.7
通讯作者：
G. Pettinari;A. Polimeni;J. H. Blokland;R. Trotta;P. Christianen;M. Capizzi;J. Maan;Xianfeng. Lu;E. Young;T. Tiedje
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文献类型：
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作者：
G. Pettinari;A. Polimeni;J. H. Blokland;R. Trotta;P. Christianen;M. Capizzi;J. Maan;Xianfeng. Lu;E. Young;T. Tiedje
我们报告了在非常大的Bi浓度范围$(x=0\text{\char21{}}10.6\mathrm{%})$中${\text{GaAs}}_{1\ensuremath{-}x}{\text{Bi}}_{x}$的激子约简质量${\ensuremath{\mu}}_{\text{exc}}$的成分依赖性。高磁场（$B$ 高达 30 T）下的光致发光表明，${\ensuremath{\mu}}_{\text{exc}}$ 快速增加，直到 $x\ensuremath{\sim}1.5\mathrm{%}$，然后围绕 $\ensuremath{\sim}0.08\text{ }{m}_{0}$ 振荡，${m}_{0}$ 为电子质量真空，最高约$x=6\mathrm{%}$。令人惊讶的是，对于 $xg8\mathrm{%}$，激子折合质量降低到 GaAs 值以下，与 $k\ensuremath{\cdot}p$ 模型的预期一致。这种行为揭示了不同浓度区间的存在，其中价带和导带的连续态在不同程度上与 Bi 相关能级杂交，从而赋予带边缘 $xl6\mathrm{%}$ 和 $xg8\mathrm{%}$ 分别的局部或带状特征。
We report the compositional dependence of the exciton reduced mass, ${\ensuremath{\mu}}_{\text{exc}}$, of ${\text{GaAs}}_{1\ensuremath{-}x}{\text{Bi}}_{x}$ in a very large Bi concentration range $(x=0\text{\char21{}}10.6\mathrm{%})$. Photoluminescence under high magnetic fields ($B$ up to 30 T) shows that ${\ensuremath{\mu}}_{\text{exc}}$ increases rapidly until $x\ensuremath{\sim}1.5\mathrm{%}$ and then oscillates around $\ensuremath{\sim}0.08\text{ }{m}_{0}$, ${m}_{0}$ being the electron mass in vacuum, up to about $x=6\mathrm{%}$. Surprisingly, for $xg8\mathrm{%}$ the exciton reduced mass decreases below the GaAs value, in agreement with the expectations of a $k\ensuremath{\cdot}p$ model. Such a behavior reveals the existence of different concentration intervals, where continuum states of the valence and conduction band hybridize with Bi-related levels at different extents, thus conferring to the band edges a localized or bandlike character for $xl6\mathrm{%}$ and $xg8\mathrm{%}$, respectively.