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Investigation of the Shape of InGaAs/GaAs Quantum Dots



Susan Y. Lehman, Alexana Roshko, Richard Mirin, John E. Bonevich


Three samples of self-assembled In0.44Ga0.56As quantum dots (QDs) grown on (001) GaAs by molecular beam epitaxy (MBE) were studied using atomic force microscopy (AFM)) and high-resolution transmission electron microscopy (TEM) in order to characterize the height, faceting, and densities of the QDs. The cross-sectional TEM images show both pyramidal dots and dots with multiple side facets. Multiple faceting has been observed only in dots more than 8.5 nm in height and allows increased dot volume without a substantial increase in base area. Addition of a GaAs capping layer is found to increase the diameter of the QDs from roughly 40 nm to as much as 200 nm. The areal QD density is found to vary up to 50 % over the central 2 cm x 2 cm section of wafer and as much as 23 % on a length scale of micrometers.
Proceedings Title
Proc., Mater. Res. Soc. Symp.
Conference Dates
December 2-6, 2002
Conference Location
Boston, MA, USA


InGaAs, quantum dots


Lehman, S. , Roshko, A. , Mirin, R. and Bonevich, J. (2003), Investigation of the Shape of InGaAs/GaAs Quantum Dots, Proc., Mater. Res. Soc. Symp., Boston, MA, USA (Accessed June 21, 2024)


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Created December 31, 2002, Updated October 12, 2021