Microstructural and optical properties of InAs/GaAs quantum dots embedded in modulation-doped AlxGa1-xAs/GaAs heterostructures

The microstructural and the optical properties of InAs/GaAs quantum-dot (QD) arrays inserted into undoped GaAs barriers embedded in an AlxGa1−xAs/GaAs were investigated by using transmission electron microscopy (TEM) and photoluminescence (PL) measurements. The TEM images and the selected-area electron diffraction patterns showed that vertically stacked InAs QD self-assembled arrays were embedded in the GaAs barriers. The temperature-dependent PL spectra showed that the peak corresponding to the interband transitions from the ground electronic subband to the ground heavy-hole band of the InAs QDs shifted to lower energy with increasing temperature. The PL intensity of the InAs dots was significantly enhanced by the modulation-doped AlxGa1−xAs/GaAs heterostructure, and the thermal activation energy of the InAs dots was decreased by the addition of the modulation-doped AlxGa1−xAs/GaAs heterostructure. The present results can help to improve the understanding of the microstructural and the optical properties...

[1]  G. Bastard,et al.  Photoluminescence of single InAs quantum dots obtained by self-organized growth on GaAs. , 1994, Physical review letters.

[2]  A. R. Kovsh,et al.  Effect of matrix on InAs self-organized quantum dots on InP substrate , 1998 .

[3]  Bowei Xu,et al.  Ordered InAs quantum dots in InAlAs matrix on (001) InP substrates grown by molecular beam epitaxy , 1998 .

[4]  S. Denbaars,et al.  Direct formation of quantum‐sized dots from uniform coherent islands of InGaAs on GaAs surfaces , 1993 .

[5]  Y. Arakawa,et al.  EFFICIENT CARRIER RELAXATION MECHANISM IN INGAAS/GAAS SELF-ASSEMBLED QUANTUM DOTS BASED ON THE EXISTENCE OF CONTINUUM STATES , 1999 .

[6]  S. Loualiche,et al.  Carrier dynamics of self-assembled InAs quantum dots on InP (311)B substrates , 1999 .

[7]  Chien-Ping Lee,et al.  Photoluminescence Study of High-Quality InGaAs/GaAs Quantum Dots on (111)B GaAs Substrates , 1998 .

[8]  M. S. Skolnick,et al.  Emission spectra and mode structure of InAs/GaAs self-organized quantum dot lasers , 1998 .

[9]  Darryl L. Smith,et al.  Piezoelectric effects in strained-layer superlattices , 1988 .

[10]  S. Salaun,et al.  Relationship between self‐organization and size of InAs islands on InP(001) grown by gas‐source molecular beam epitaxy , 1995 .

[11]  Albert-László Barabási,et al.  Self-assembled island formation in heteroepitaxial growth , 1997, cond-mat/9703252.

[12]  J. Groenen,et al.  Strain in InAs islands grown on InP(001) analyzed by Raman spectroscopy , 1996 .

[13]  J. Brault,et al.  Strong normal-incidence infrared absorption in self-organized InAs/InAlAs quantum dots grown on InP(001) , 1999 .

[14]  P. Desjardins,et al.  METALORGANIC VAPOR PHASE EPITAXY OF COHERENT SELF-ASSEMBLED INAS NANOMETER-SIZED ISLANDS IN INP(001) , 1997 .

[15]  Gerhard Abstreiter,et al.  POLARIZATION DEPENDENT PHOTOCURRENT SPECTROSCOPY OF INAS/GAAS QUANTUM DOTS , 1999 .

[16]  Zhan-guo Wang,et al.  Growth mode and strain relaxation of InAs on InP (111)A grown by molecular beam epitaxy , 1999 .

[17]  D. Bimberg,et al.  Temperature dependent optical properties of self-organized InAs/GaAs quantum dots , 1999 .

[18]  Yozo Shimada,et al.  Bound-to-continuum intersubband photoconductivity of self-assembled InAs quantum dots in modulation-doped heterostructures , 1999 .