Suppression of dislocations by Sb spray in the vicinity of InAs/GaAs quantum dots |
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| Authors: | Liping Dai Stephen P Bremner Shenwei Tan Shuya Wang Guojun Zhang Zongwen Liu |
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| Affiliation: | 1.State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China;2.Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney 2006, Australia;3.School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052, Australia |
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| Abstract: | The effect of Sb spray prior to the capping of a GaAs layer on the structure and properties of InAs/GaAs quantum dots (QDs) grown by molecular beam epitaxy (MBE) is studied by cross-sectional high-resolution transmission electron microscopy (HRTEM). Compared to the typical GaAs-capped InAs/GaAs QDs, Sb-sprayed QDs display a more uniform lens shape with a thickness of about 3 ~ 4 nm rather than the pyramidal shape of the non-Sb-sprayed QDs. Particularly, the dislocations were observed to be passivated in the InAs/GaAs interface region and even be suppressed to a large extent. There are almost no extended dislocations in the immediate vicinity of the QDs. This result is most likely related to the formation of graded GaAsSb immediately adjacent to the InAs QDs that provides strain relief for the dot/capping layer lattice mismatch.PACS81.05.Ea; 81.07.-b; 81.07.Ta |
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| Keywords: | Quantum dots InAs HRTEM Dislocations |
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