Structure and optical anisotropy of vertically correlated submonolayer InAs/GaAs quantum dots

A vertically correlated submonolayer (VCSML) InAs/GaAs quantum-dot (QD) heterostructure was studied using transmission electron microscopy, high-resolution x-ray diffraction (HRXRD) and polarization-dependent photoluminescence. The HRXRD (004) rocking curve was simulated using the Tagaki–Taupin equations. Excellent agreement between the experimental curve and the simulation is achieved assuming that indium-rich VCSML QDs are embedded in a quantum well (QW) with lower indium content and an observed QD coverage of 10%. In the VCSML QDs, the vertical lattice mismatch of the InAs monolayer with respect to GaAs is around 1.4%, while the lattice mismatch in the QW is negligible. The photoluminescence is transverse magnetic—polarized in the edge geometry.

[1]  I. P. Soshnikov,et al.  Lasing in structures with InAs quantum dots in an (Al, Ga)As matrix grown by submonolayer deposition , 1999 .

[2]  J. E. Bernard,et al.  Is there an elastic anomaly for a (001) monolayer of InAs embedded in GaAs , 1994 .

[3]  Weinberg,et al.  Initial stages of InAs epitaxy on vicinal GaAs(001)-(2 x 4). , 1994, Physical review. B, Condensed matter.

[4]  Bernard,et al.  Stability of coherently strained semiconductor superlattices. , 1990, Physical review letters.

[5]  Nikolai N. Ledentsov,et al.  3.9 W CW power from sub-monolayer quantum dot diode laser , 1999 .

[6]  D. Bimberg,et al.  High‐resolution x‐ray diffraction of self‐organized InGaAs/GaAs quantum dot structures , 1996 .

[7]  S. Takagi.  Dynamical theory of diffraction applicable to crystals with any kind of small distortion , 1962 .

[8]  Mikhail V. Maximov,et al.  0.94 µm diode lasers based on Stranski-Krastanow and sub-monolayer quantum dots , 2000 .

[9]  Wood,et al.  Epitaxial effects on coherent phase diagrams of alloys. , 1989, Physical review. B, Condensed matter.

[10]  Yamaguchi,et al.  Electronic structure of an InAs monomolecular plane in GaAs. , 1990, Physical review. B, Condensed matter.

[11]  D. Taupin,et al.  Théorie dynamique de la diffraction des rayons X par les cristaux déformés , 1964 .

[12]  W. Bartels,et al.  Determination of the lattice constant of epitaxial layers of III-V compounds , 1978 .

[13]  E. Towe,et al.  Structural characterization of InAs/GaAs quantum-dot nanostructures , 2001 .

[14]  Nikolai N. Ledentsov,et al.  Optical anisotropy in vertically coupled quantum dots , 1999 .

[15]  I. Krestnikov,et al.  Quantum dots formed by ultrathin insertions in wide-gap matrices , 2000 .

[16]  Dieter Bimberg,et al.  Spontaneous ordering of nanostructures on crystal surfaces , 1999 .

[17]  Nikolai N. Ledentsov,et al.  Quantum dot heterostructures , 1999 .

[18]  Nikolai N. Ledentsov,et al.  Arrays of Two-Dimensional Islands Formed by Submonolayer Insertions: Growth, Properties, Devices , 2001 .