DIRECT FORMATION OF QUANTUM-SIZED DOTS FROM UNIFORM COHERENT ISLANDS OF INGAAS ON GAAS-SURFACES
DIRECT FORMATION OF QUANTUM-SIZED DOTS FROM UNIFORM COHERENT ISLANDS OF INGAAS ON GAAS-SURFACES
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DOI：
10.1063/1.110199
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发表时间：
1993-12-06
影响因子：
4
通讯作者：
PETROFF, PM
中科院分区：
文献类型：
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作者：
LEONARD, D;KRISHNAMURTHY, M;PETROFF, PM
高应变 InGaAs 在 GaAs 上生长初始阶段的 2D-3D 生长模式转变用于获得量子尺寸的点结构。透射电子显微照片显示，当 In0.5Ga0.5As 的生长恰好在 2D-3D 转变开始时中断时，就会产生 InGaAs 的无位错岛（点）。尺寸分布表明这些点的直径约为 300 埃，并且非常均匀，误差在该平均尺寸的 10% 以内。面点密度可在 10(9) 和 10(11) cm-2 之间变化。点尺寸的均匀性可以通过基于应变导致的吸附原子附着概率降低的机制来解释。通过比较带点和不带点的样品，我们明确地证明了这些岛在约 1.2 eV 处的光致发光。点的发光强度大于或等于下面的参考量子阱的发光强度。
The 2D-3D growth mode transition during the initial stages of growth of highly strained InGaAs on GaAs is used to obtain quantum-sized dot structures. Transmission electron micrographs reveal that when the growth of In0.5Ga0.5As is interrupted exactly at the onset of this 2D-3D transition, dislocation-free islands (dots) of the InGaAs result. Size distributions indicate that these dots are approximately 300 angstrom in diameter and remarkably uniform to within 10% of this average size. The areal dot densities can be varied between 10(9) and 10(11) cm-2. The uniformity of the dot sizes is explained by a mechanism based on reduction in adatom attachment probabilities due to strain. We unambiguously demonstrate photoluminescence at approximately 1.2 eV from these islands by comparing samples with and without dots. The luminescent intensities of the dots are greater than or equal to those of the underlying reference quantum wells.