X-Ray Diffraction Analysis on Gallium-Indium Interdiffusion in Quantum Dot Superlattices

• 来源期刊: 中国物理快报（英文版）
• 学科: 物理学
• 年，卷（期）: 2001,（6）
• 页码范围: 810-812
• 页数: 3页
• 分类号: O4
• 语种: 英文

摘要

Thermal-induced interdiffusion in InAs/GaAs quantum dot superlattices is studied by high-resolution x-raydiffraction rocking curve and photoluminescence techniques. With increasing annealing temperatures, up to300meV a blueshift of the emission peak position and down to 16.6meV a narrowing of the line width are foundin the photoluminescence spectra, and respective intensity of the higher-order satellite peaks to lower-order onesin the x-ray rocking curves decreases. Dynamical theory is employed to simulate the measured x-ray diffractiondata. Excellent agreement between the experimental curves and the simulations is achieved when the composition, thickness and stress variations caused by interdiffusion are taken into account. It is found that the significantIn-Ga intermixing occurs even in the as-grown InAs/GaAs quantum dots. The estimated diffusion coefficient is1.8 × 10-17cm2.s-1 at 650 ℃, 3.2 × 10-17cm2·s-1 at 750 ℃, and 1.2 × 10-14 cm2.s-1 at 850℃.