Nano-Photoluminescence Studies of Self-Assembled Quantum Dots

1999 ◽  
Vol 583 ◽  
Author(s):  
H. Htoon ◽  
Hongbin Yu ◽  
D. Kulik ◽  
J. W. Keto ◽  
O. Baklenov ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Stark Effect ◽  
Nanometer Scale ◽  
Far Field ◽  
Quantum Confined Stark Effect ◽  
Carrier Transfer ◽  
Field Dependent ◽  
Self Assembled ◽  
Photoluminescence Studies ◽  
Individual Self

AbstractTwo simple and effective far-field-optics-based methods capable of isolating photoluminescence peaks of different individual self assembled quantum dots (SAQD's) with nanometer scale precision are presented. By using these methods, we performed the temperature and electric field dependent studies on the optical properties of SAQD's. We found temperature induced inter-dot carrier transfer among neighboring quantum dots (QD's) and observed the quantum confined stark effect (QCSE).

Quantum-confined Stark effect and built-in dipole moment in self-assembled InAs∕GaAs quantum dots

2004 ◽  
Vol 85 (14) ◽  
pp. 2791-2793 ◽  
Author(s):  
Peng Jin ◽  
C. M. Li ◽  
Z. Y. Zhang ◽  
F. Q. Liu ◽  
Y. H. Chen ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Dipole Moment ◽  
Stark Effect ◽  
Quantum Confined Stark Effect ◽  
Quantum Confined ◽  
Self Assembled

Quantum Confined Stark Effect and Permanent Dipole Moment of InAs–GaAs Self-Assembled Quantum Dots

2000 ◽  
Vol 178 (1) ◽  
pp. 269-275 ◽  
Author(s):  
P.W. Fry ◽  
I.E. Itskevich ◽  
D.J. Mowbray ◽  
M.S. Skolnick ◽  
J. Barker ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Dipole Moment ◽  
Stark Effect ◽  
Permanent Dipole Moment ◽  
Quantum Confined Stark Effect ◽  
Quantum Confined ◽  
Self Assembled

Photocurrent Spectroscopy of InAs/GaAs Self-Assembled Quantum Dots: Observation of a Permanent Dipole Moment

1999 ◽  
Vol 571 ◽  
Author(s):  
P.W. Fry ◽  
I.E. Itskevich ◽  
D.J. Mowbray ◽  
M.S. Skolnick ◽  
J.A. Barker ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Dipole Moment ◽  
Stark Effect ◽  
Permanent Dipole Moment ◽  
Thermal Excitation ◽  
Zero Field ◽  
Quantum Confined Stark Effect ◽  
Photocurrent Spectroscopy ◽  
Self Assembled ◽  
Carrier Escape

ABSTRACTPhotocurrent spectroscopy of InAs/GaAs self-assembled quantum dots, studied as a function of applied electric field, is used to probe the nature of the confined electronic states. A field asymmetry of the quantum confined Stark effect is observed, consistent with the dots possessing a permanent dipole moment. The sign of this dipole indicates that for zero field the hole wavefunction lies above that of the electron, in disagreement with the predictions of all recent calculations. Comparison with a theoretical model demonstrates that the experimentally determined alignment of the electron and hole can only be explained if the dots contain a nonzero and non-uniform Ga content. The role of two different carrier escape mechanisms, tunneling and thermal excitation, is studied.

Quantum Confined Stark Effect in Single Self-Assembled CdTe Quantum Dots

2010 ◽  
Author(s):  
Ł. Kłopotowski ◽  
A. Kudelski ◽  
P. Wojnar ◽  
A. I. Tartakovskii ◽  
M. S. Skolnick ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Stark Effect ◽  
Cdte Quantum Dots ◽  
Quantum Confined Stark Effect ◽  
Quantum Confined ◽  
Self Assembled

GaN Quantum Dots Grown at High Temperatures by Molecular Beam Epitaxy

2004 ◽  
Vol 831 ◽  
Author(s):  
Tao Xu ◽  
Adrian Williams ◽  
Christos Thomidis ◽  
Theodore D. Moustakas ◽  
Lin Zhou ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Temperatures ◽  
Stark Effect ◽  
Spatial Density ◽  
Height Distribution ◽  
Quantum Confined Stark Effect ◽  
Sapphire Substrates ◽  
Superlattice Structure ◽  
Bulk Gan ◽  
Photoluminescence Studies

ABSTRACTIn this paper we report the growth by MBE of GaN quantum dot superlattices (QDSLs) with AlN barriers on (0001) sapphire substrates at relatively high temperatures (770 °C) by the modified Stranski-Krastanov method. TEM studies indicate that the GaN QDs are truncated pyramids. We find that the height distribution of the dots depends strongly on the number of GaN monolayer coverage on the top of AlN. Specifically, we find that the height distribution consists of two Gaussian distributions (bimodal) for coverage of 3 and 4 MLs, and becomes single Gaussian distribution for 5 and 6 MLs of coverage. Furthermore, we find that the density of quantum dots increases with the degree of coverage and saturates at 2×1011 dots/cm2. The number of stacks in the superlattice structure was also found to lead to bimodal height distribution of the QDs. Ordering of the quantum dots was accomplished by thermal annealing of the sapphire substrates at 1400 °C prior to the growth of GaN QDs. The annealing process reveals the vicinal steps due to the miscut of the substrates and the GaN QDs were found to line up along those steps. Photoluminescence studies show a broad luminescence spectrum centered at 3 eV which is red shifted with respect to that of bulk GaN and is consistent with internal fields due to polarization (Quantum Confined Stark Effect). Furthermore, we find that the luminescence intensity increases with the number of stacks in the superlattice structure due to higher spatial density of QDs.

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