Shape Engineered InAs Quantum Dots with Stabilized Electronic Properties

2002 ◽  
Vol 737 ◽  
Author(s):  
V. Tokranov ◽  
M. Yakimov ◽  
A. Katsnelson ◽  
K. Dovidenko ◽  
M. Lamberti ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
State Energy ◽  
Growth Parameters ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Temperature Threshold ◽  
Inas Quantum Dots ◽  
Subsequent Heating ◽  
Heating Up

ABSTRACTWe have studied the influence of overgrowth procedure and a few monolayer-thick AlAs overlayer on the properties of self-assembled InAs quantum dots (QDs) using scanning electron microscopy (SEM) and photoluminescence (PL). PL spectroscopy was used to optimize optical properties of the QDs by shape engineering (QD truncation) through adjustment of the thickness of overlayers and temperature of the subsequent heating. QDs with 6 nm - thick overlayer with subsequent heating up to 560°C was found to have the highest PL intensity at room temperature and the lowest FWHM, 29 meV. Ground state energy of the truncated QDs is very stable against variations of growth parameters. 1.23 μm edge-emitting laser of triple-layer QD structure demonstrated room temperature threshold current density, 74 A/cm2.

InAs Quantum Dots in AlAs/GaAs Short Period Superlattices: Structure, Optical Characteristics and Laser Diodes

2001 ◽  
Vol 707 ◽  
Author(s):  
Vadim Tokranov ◽  
M. Yakimov ◽  
A. Katsnelson ◽  
K. Dovidenko ◽  
R. Todt ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Inas Quantum Dots ◽  
Transmission Electron ◽  
Short Period ◽  
Short Period Superlattices ◽  
Emitting Lasers ◽  
Cladding Layers

ABSTRACTThe influence of two monolayer - thick AlAs under- and overlayers on the formation and properties of self-assembled InAs quantum dots (QDs) has been studied using transmission electron microscopy (TEM) and photoluminescence (PL). Single sheets of InAs QDs were grown inside a 2ML/8ML AlAs/GaAs short-period superlattice with various combinations of under- and overlayers. It was found that 2.4ML InAs QDs with GaAs underlayer and 2ML AlAs overlayer exhibited the lowest QD surface density of 4.2x1010 cm-2 and the largest QD lateral size of about 19 nm as compared to the other combinations of cladding layers. This InAs QD ensemble has also shown the highest room temperature PL intensity with a peak at 1210 nm and the narrowest linewidth, 34 meV. Fabricated edge-emitting lasers using triple layers of InAs QDs with AlAs overlayer demonstrated 120 A/cm2 threshold current density and 1230 nm emission wavelength at room temperature. Excited state QD lasers have shown high thermal stability of threshold current up to 130°C.

InAs quantum dots in AlAs/GaAs short period superlattices: structure, optical characteristics and laser diodes

2001 ◽  
Vol 692 ◽  
Author(s):  
Vadim Tokranov ◽  
M. Yakimov ◽  
A. Katsnelson ◽  
K. Dovidenko ◽  
R. Todt ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Inas Quantum Dots ◽  
Transmission Electron ◽  
Short Period ◽  
Short Period Superlattices ◽  
Emitting Lasers ◽  
Cladding Layers

AbstractThe influence of two monolayer - thick AlAs under- and overlayers on the formation and properties of self-assembled InAs quantum dots (QDs) has been studied using transmission electron microscopy (TEM) and photoluminescence (PL). Single sheets of InAs QDs were grown inside a 2ML/8ML AlAs/GaAs short-period superlattice with various combinations of under- and overlayers. It was found that 2.4ML InAs QDs with GaAs underlayer and 2ML AlAs overlayer exhibited the lowest QD surface density of 4.2×1010 cm-2 and the largest QD lateral size of about 19 nm as compared to the other combinations of cladding layers. This InAs QD ensemble has also shown the highest room temperature PL intensity with a peak at 1210 nm and the narrowest linewidth, 34 meV. Fabricated edge-emitting lasers using triple layers of InAs QDs with AlAs overlayer demonstrated 120 A/cm2 threshold current density and 1230 nm emission wavelength at room temperature. Excited state QD lasers have shown high thermal stability of threshold current up to 130°C.

1.5 micron InAs quantum dot lasers based on metamorphic InGaAs/GaAs heterostructures.

2003 ◽  
Vol 794 ◽  
Author(s):  
V.M. Ustinov ◽  
A.E. Zhukov ◽  
A.R. Kovsh ◽  
N.A. Maleev ◽  
S.S. Mikhrin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Active Region ◽  
Quantum Wells ◽  
Gaas Substrate ◽  
Room Temperature ◽  
Internal Quantum Efficiency ◽  
Characteristic Temperature ◽  
Optical Loss ◽  
Threshold Current ◽  
Temperature Threshold

ABSTRACT1.5 micron range emission has been realized using the InAs quantum dots embedded into the metamorphic InGaAs layer containing 20% of InAs grown by MBE on a GaAs substrate. Growth regimes were optimized to reduce significantly the density of dislocations propagating into the active layer from the lattice mismatched interface. 2 mm long InGaAs/InGaAlAs lasers with 10 planes of quantum dots in the active region showed threshold current density about 1.4 kA/cm2 with the external differential efficiency as high as 38%. Lasing wavelength depends on the optical loss being in the 1.44–1.49 micron range at room temperature. On increasing the temperature the wavelength reaches 1.515 micron at 85C while the threshold current characteristic temperature of 55–60K was estimated. High internal quantum efficiency (η>60%)and low internal losses (α=3–4 cm ) were realized. Maximum room temperature output power in pulsed regime as high as 5.5 W for 100 micron wide stripe was demonstrated. Using the same concept 1.3 micron InGaAs/InGaAlAs quantum well lasers were fabricated. The active region contained quantum wells with high (∼40%) indium content which was possible due to the intermediate InGaAs strain relaxation layer. 1 mm stripe lasers showed room temperature threshold current densities about 3.3 kA/cm (λ=1.29 micron) and 400 A/cm2 at 85K. Thus, the use of metamorphic InGaAs layers on GaAs substrate is a very promising approach for increasing the emission wavelength of GaAs based lasers.

1.5 micron InAs quantum dot lasers based on metamorphic InGaAs/GaAsheterostructures.

2003 ◽  
Vol 799 ◽  
Author(s):  
V. M. Ustinov ◽  
A. E. Zhukov ◽  
A. R. Kovsh ◽  
N. A. Maleev ◽  
S. S. Mikhrin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Active Region ◽  
Quantum Wells ◽  
Gaas Substrate ◽  
Room Temperature ◽  
Internal Quantum Efficiency ◽  
Characteristic Temperature ◽  
Optical Loss ◽  
Threshold Current ◽  
Temperature Threshold

ABSTRACT1.5 micron range emission has been realized using the InAs quantum dots embedded into the metamorphic InGaAs layer containing 20% of InAs grown by MBE on a GaAs substrate. Growth regimes were optimized to reduce significantly the density of dislocations propagating into the active layer from the lattice mismatched interface. 2 mm long InGaAs/InGaAlAs lasers with 10 planes of quantum dots in the active region showed threshold current density about 1.4 kA/cm2 with the external differential efficiency as high as 38%. Lasing wavelength depends on the optical loss being in the 1.44–1.49 micron range at room temperature. On increasing the temperature the wavelength reaches 1.515 micron at 85C while the threshold current characteristic temperature of 55–60K was estimated. High internal quantum efficiency (η>60%) and low internal losses (α=3–4 cm-1 ) were realized. Maximum room temperature output power in pulsed regime as high as 5.5 W for 100 micron wide stripe was demonstrated. Using the same concept 1.3 micron InGaAs/InGaAlAs quantum well lasers were fabricated. The active region contained quantum wells with high (∼40%) indium content which was possible due to the intermediate InGaAs strain relaxation layer. 1 mm stripe lasers showed room temperature threshold current densities about 3.3 kA/cm2 (λ=1.29 micron) and 400 A/cm2 at 85K. Thus, the use of metamorphic InGaAs layers on GaAs substrate is a very promising approach for increasing the emission wavelength of GaAs based lasers.

Formation of Stacked Self-Assembled InAs Quantum Dots in GaAs Matrix for Laser Applications

1995 ◽  
Vol 417 ◽  
Author(s):  
V. M. Ustinov ◽  
A. Yu. Egorov ◽  
A. E Zhukov ◽  
N. N. Ledentsov ◽  
M. V. Maksimov ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Current Density ◽  
Ground State ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Laser Applications ◽  
Inas Quantum Dots ◽  
Gaas Matrix ◽  
Single Sheet ◽  
Thermal Stability Of

AbstractVertically coupled InAs quantum dots have been synthesized by MBE through successive deposition of InAs dot sheets and thin GaAs spacers. The energy of ground state transition in PL spectra has been found to depend on a number of dot sheets and the spacer width. Injection laser based on vertically coupled quantum dots demonstrated lasing via the ground state of quantum dots in the entire 80K-300K temperature range. Lower threshold current density and wider range of the thermal stability of threshold current density as compared to the single sheet quantum dot laser have been observed.

1.3 [micro sign]m InAs∕GaAs multilayer quantum-dot laser with extremely low room-temperature threshold current density

2004 ◽  
Vol 40 (22) ◽  
pp. 1412 ◽  
Author(s):  
I.R. Sellers ◽  
H.Y. Liu ◽  
K.M. Groom ◽  
D.T. Childs ◽  
D. Robbins ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Current Density ◽  
Room Temperature ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Temperature Threshold ◽  
Quantum Dot Laser

740 nm InP∕GaInP quantum-dot laser with 190 A cm−2 room temperature threshold current density

2005 ◽  
Vol 41 (5) ◽  
pp. 247 ◽  
Author(s):  
J. Lutti ◽  
P.M. Smowton ◽  
G.M. Lewis ◽  
A.B. Krysa ◽  
J.S. Roberts ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Current Density ◽  
Room Temperature ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Temperature Threshold ◽  
Quantum Dot Laser
Sign in / Sign up

Export Citation Format

Share Document