Long-Wavelength Photoluminescence from Stacked Layers of High-Quality Type-II GaSb/GaAs Quantum Rings

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• 作者：Peter J. Carrington ; Robert J. Young ; Peter D. Hodgson ; Ana M. Sanchez ; Manus Hayne ; Anthony Krier
• 刊名：Crystal Growth & Design
• 出版年：2013
• 出版时间：March 6, 2013
• 年：2013
• 卷：13
• 期：3
• 页码：1226-1230
• 全文大小：317K
• 年卷期：v.13,no.3(March 6, 2013)
• ISSN：1528-7505

文摘

We report the successful molecular-beam epitaxial growth of 10 stacked layers of GaSb/GaAs quantum rings using a new procedure. Exact control of the arsenic flux during capping helps to reduce the strong group-V As鈥揝b exchange reactions, enabling the rings to be capped at the same growth temperature (480 掳C) without dissolution. X-ray diffraction and transmission electron microscopy indicate excellent structural quality and uniformity with no threading dislocations. This is due to the reduction in the average strain through the quantum-ring formation. The total ring density in the stacks is 1 脳 10¹¹ cm^鈥?. An unusually long-wavelength quantum-ring photoluminescence peak of 1.3 渭m is observed at low temperature, which is attributed to a reduction in the quantum-ring charging due to lower unintentional p-doping in the GaAs cap layer. The impact that this effect will have on future device designs in solar cells and lasers is also discussed.