Electric-field effects on above-barrier states in a GaAs/AlxGa1-xAs superlattice.
Electric-field effects on above-barrier states in a GaAs/AlxGa1-xAs superlattice.
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GaAs/AlxGa1-xAs 超晶格中势垒之上的电场效应。
DOI：
10.1103/physrevb.51.4236
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Fujiwara
中科院分区：
文献类型：
--
作者：
Nakayama;Ando;Tanaka;Nishimura;Schneider;Fujiwara
我们研究了p型和n型Al 0.3 Ga 0.7 As层包覆的GaAs (7.0 nm)/Al 0.1 Ga 0.9 As (3.5 nm)超晶格中上述势垒态的电场效应，使用电反射光谱检测带间光学跃迁，并使用转移矩阵方法计算本征能。结果表明，与上述势垒态相关的光学跃迁能量的电场依赖性表现出与低于势垒势的斯塔克梯态类似的特征。此外，从电反射信号的线形变化发现，上势垒态与空间上分离的下势垒态谐振耦合。线形变化是由键合和反键合态的形成以及耦合空间上的波函数离域引起的。传递矩阵分析很好地解释了上述实验结果。
We have investigated electric-field effects on the above-barrier states in a GaAs (7.0 nm)/Al 0.1 Ga 0.9 As (3.5 nm) superlattice clad by p-type and n-type Al 0.3 Ga 0.7 As layers using electroreflectance spectroscopy for detecting the interband optical transitions and using a transfer-matrix method for calculating the eigenenergies. It is demonstrated that the electric-field dependence of the energies of the optical transitions associated with the above-barrier states exhibits a similar feature of the Stark-ladder states below the barrier potential. In addition, it is found from the line-shape change of the electroreflectance signals that the above-barrier state resonantly couples with the spatially separated below-barrier state. The line-shape change results from the formation of bonding and antibonding states and wave-function delocalization over the coupling space. The transfer-matrix analysis explains the above experimental results reasonably well.