ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The formation process of a bimodal distribution of low-pressure metal-organic-vapor-phase-epitaxy (LP–MOVPE) grown InGaAs/GaAs quantum dots (QDs) is studied by transmission electronic microscopy. We demonstrate that in our growth conditions, the deposition of an InGaAs layer on an already existing array of InAs formed QDs leads to the nucleation of a second dots population. The InAs QDs nucleation is diffusion limited, inducing a low dots density due to the high In-atoms diffusion length typical of the MOVPE. On the contrary, the InGaAs QDs nucleation is enhanced by the roughness of the highly strained wetting layer of the InAs QDs, leading to higher density. The study of the photoluminescence spectra shows that the nucleation of InGaAs only occurs when the deposited InAs thickness exceeds about 1.4 monolayers, i.e., after the formation of the InAs QDs. © 2002 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1448887
Permalink