Cathodoluminescence atomic scale images of monolayer islands at GaAs/GaAlAs interfaces
Cathodoluminescence atomic scale images of monolayer islands at GaAs/GaAlAs interfaces
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GaAs/GaAlAs 界面单层岛的阴极发光原子尺度图像
DOI：
10.1116/1.583710
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Jeffrey N. Miller
中科院分区：
文献类型：
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作者：
D. Bimberg;J. Christen;T. Fukunaga;H. Nakashima;D. Mars;Jeffrey N. Miller
首次报道了相差2.8A[1单分子层(ML)]高度的GaAsAlGaAs异质界面生长岛和量子阱柱状结构的直接图像。结构采用分子束外延生长，界面处≊生长中断2min。获得这些图像的方法是扫描阴极发光。研究了这些岛的横向伸展与生长条件的关系。对于固定生长速率的≊0.5ML/S，随着生长温度从Tg=600提高到660μ°C，平均岛尺寸从6-7μm减小到2 m。显然，生长过程从平面变为三维。对于较低的生长温度和生长速率，这种孤岛的横向扩展可以大于载流子扩散长度。在这种情况下，载体的岛间热化在很大程度上受到抑制。给出了量子阱界面粗糙度随生长速度的增加而减小的定量信息。
Direct images of growth islands differing by 2.8 A [1 monolayer (ML)] height at GaAs/AlGaAs heterointerfaces and of the columnar structure of quantum wells are reported for the first time. The structures are grown by molecular‐beam epitaxy (MBE) with interruptions of the growth of ≊2 min at the interfaces. The method used to obtain these images is scanning cathodoluminescence. The dependence of the lateral extension of these islands on growth conditions is investigated. For fixed growth rate rs≊0.5 ML/s the mean island size decreases from 6–7 μm to 2 μm upon an increase of growth temperature from Tg=600 to 660 °C. Apparently the growth process changes from a planar to a three‐dimensional one. For low‐growth temperature and rate the lateral extension of such islands can be larger than the carrier diffusion length. Under these conditions interisland thermalization of carriers is largely suppressed. Quantitative information on the reduction of roughness of the quantum well interfaces with increasing growth i...