PDSelf-Formation of High-Uniformity and High-Density Quantum Dots
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@Self-formation techniques based on Stranski-Krastanov (SK) growth mode are much attractive for fabrication of
dense quantum dots (QDs) with high crystal quality and have been studied actively for more than ten years.
However, the formation mechanism of SK QDs has not been understood clearly. In order to realize some device
applications, control of SK QDs must be more improved and is still an open challenge. In particular, a large
inhomogeneous broadening in QD energy level is an important problem. So far, several growth techniques have been
attempted to fabricate uniform QDs. However, it is difficult to achieve a narrow photoluminescence (PL) linewidth
of less than 20 meV for a single QD layer. Recently, we have found a self size-limiting effect due to the facet
formation and have demonstrated a highly uniform single QD-layer of the InAs, which revealed 18.6 meV in PL
linewidth. In addition, high QD density is also requested for realization of QD lasers with such high performance.
More recently, we have been attempting a new growth method, where InAs QDs were grown on one-monolayer-thick GaSb
layer, formed on the GaAs(001) substrate. The underlying GaSb layer enhanced the nucleation of the 3D dot, and
high QD density of 1~1011 cm-2 was achieved successfully.
Related papers:
K.Yamaguchi and T.Kanto : g Self-assembled InAs Quantum Dots on GaSb/GaAs(001) Layers by Molecular Beam Epitaxy g, J. Cryst. Growth, Vol.275 (2005) pp.e2269-e2273.
Y.Kobayashi and K.Yamaguchi : g Control of Photoluminescence Wavelength from Uniform InAs Qunatum Dots by Annealing g, Appl. Surf. Sci., Vol.244 (2005) pp.88-91.
K.Yamaguchi, T.Kaizu, T.Kanto and Y.Suzuki : g Self-Formation of Uniform InAs Quantum Dots and Quantum-Dot Chains g, Trans. MRS-J, Vol.29, No.1 (2004) 117-121.
T.Kaizu and K.Yamaguchi : g Facet Formation of Uniform InAs Quantum Dots by Molecular Beam Epitaxy g, Jpn. J. Appl. Phys., Vol.42, No.6B (2003) pp.4166-4168.
T.Kaizu and K.Yamaguchi : g Uniform Formation of Two-dimensional and Three-dimensional InAs Islands on GaAs by Molecular Beam Epitaxy g, Jpn. J. Appl. Phys., Vol.42, No. 4A (2003) pp.1705-1708.
K.Yamaguchi, T.Kaizu, K.Yujobo and Y.Saito: g Uniform Formation Process of Self-Organized InAs Quantum Dots g, J. Cryst. Growth, Vol.237-239 (2002) pp.1301-1306.
T.Kaizu and K.Yamaguchi : g Self Size-Limiting Process of InAs Quantum Dots Grown by Molecular Beam Epitaxy g, Jpn. J. Appl. Phys., Vol.40, No.3A (2001) pp.1885-1887.
K.Yamaguchi, K.Yujobo and T.Kaizu : g Stranski-Krastanov Growth of InAs Quantum Dots with Narrow Size Distribution g, Jpn. J. Appl. Phys., Vol.39, No.12A (2000) pp.L1245-L1248.