Multiple stacking of self-assembled InAs quantum dots embedded by GaNAs strain compensating layers
- Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan)
We have investigated a growth technique to realize high-quality multiple stacking of self-assembled InAs quantum dots (QDs) on GaAs (001) substrates, in which GaN{sub x}As{sub 1-x} dilute nitride material was used as a strain compensation layer (SCL). The growth was achieved by atomic hydrogen-assisted rf molecular beam epitaxy, and the effect of strain compensation was systematically investigated by using high-resolution x-ray diffraction measurements. By controlling the net average lattice strain to a minimum by covering each QD layer with a 40-nm-thick GaN{sub 0.005}As{sub 0.995} SCL, we obtained a superior QD structure with no degradation in size homogeneity. Further, no dislocations were generated even after 30 layers of stacking, and the area density of QDs amounted to as high as 3x10{sup 12} cm{sup -2}. The photoluminescence peak linewidth was improved by about 22% for QDs embedded in GaNAs SCLs as the accumulation of lattice strain with increasing growth of QD layers was avoided, which would otherwise commonly lead to degradation of size homogeneity and generation of dislocations.
- OSTI ID:
- 20884773
- Journal Information:
- Journal of Applied Physics, Vol. 100, Issue 8; Other Information: DOI: 10.1063/1.2359623; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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