Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1790692 | Journal of Crystal Growth | 2013 | 6 Pages |
Abstract
This paper reports on an in-situ growth process used to optimize InAs/GaAs quantum dot (QD) multilayer structures grown on (001) GaAs substrate by chemical beam epitaxy (CBE). Defects related to the incoherently relaxed InAs clusters are found to alter the QD nucleation mechanism on the subsequent layers, leading to reduced QD density and photoluminescence intensity. The formation of poor crystalline quality clusters is avoided by growing the GaAs spacer layers in a two-step process. The technique consists in covering the InAs QD layer with a 10 nm-thick GaAs layer grown at 465 °C, and then removing the excess indium contained in the uncapped portion of the clusters by increasing the temperature to 565 °C for 10 min before the deposition of the remaining GaAs spacer layer. Morphological investigation shows that the QD density and size distribution obtained in the first layer are preserved up to the tenth layer. The QD integrated photoluminescence intensity is found to increase linearly with the number of stacked layers. These results are very promising for chemical beam growth of high performance intermediate-band solar cells.
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Jihene Zribi, Bouraoui Ilahi, Denis Morris, Vincent Aimez, Richard Arès,