Influence of transport properties on the excitation spectra of GaAs/AlxGa1-xAs superlattices and bulk layers
Influence of transport properties on the excitation spectra of GaAs/AlxGa1-xAs superlattices and bulk layers
复制标题
输运特性对 GaAs/AlxGa1-xAs 超晶格和体层激发光谱的影响
DOI：
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发表时间：
1988
期刊：
影响因子：
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通讯作者：
A. Regreny
中科院分区：
文献类型：
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作者：
A. Chomette;B. Lambert;B. Clerjaud;F. Clérot;H. W. Liu;A. Regreny
在GaAs/AlxGa1-xAs超晶格、GaAs和AlGaAs外延层中，当距表面给定距离处存在逃逸机制时，光致发光激发光谱的结果强烈依赖于载流子迁移率，即载流子在穿过有源层后有可能从有源层逃逸。当没有足够靠近表面的逃逸机制时，除了激子共振之外，激发光谱大致平坦。当逃逸机制存在于距表面约 1 μm 的距离处时，如果迁移率足够高，如 GaAs 和周期小于约 70 AA 的超晶格（对于 x 约为 0.3 且势阱和势垒宽度几乎相等），激发光谱会呈现出递减的高能尾部；相反，在具有更大周期的 AlGaAs 和超晶格中，激发光谱与没有逃逸机制的类似样品具有相同的形状。对于器件应用来说，具有小周期的超晶格构成了比等效 AlGaAs 层更好的结构。
In GaAs/AlxGa1-xAs superlattices, GaAs and AlGaAs epitaxial layers, the results of photoluminescence excitation spectroscopy are shown to depend strongly on carrier mobilities when, at a given distance from the surface, an escape mechanism exists, i.e. a possibility for carriers to escape from the active layer after moving through it. When there is no escape mechanism close enough to the surface, excitation spectra are roughly flat apart from the excitonic resonances. When an escape mechanism is present at a distance of around 1 mu m from the surface, if the mobility is high enough as in GaAs and superlattices with periods smaller than about 70 AA (for x approximately 0.3 and nearly equal well and barrier widths), the excitation spectra exhibit a decreasing high-energy tail; on the contrary in AlGaAs and superlattices with greater periods the excitation spectra have the same shape as in similar samples without an escape mechanism. Superlattices with small periods constitute better structures than equivalent AlGaAs layers for device applications.