Electroluminescence from One-Dimensionally Self-Aligned Si-Based Quantum Dots with High Areal Dot Density

In this paper, semiconductor quantum dot structures for mid-infrared emission were self-assembled on InP substrate by using metal–organic vapor phase epitaxy growth. The InAs quantum dots grown at different conditions have been investigated. To improve the grown quantum dot's shape, the dot density and the dot size uniformity, a two-step growth method has been used and investigated. By changing the composition of the In x Ga 1-x As matrix layer of the InAs / In x Ga 1-x As / InP quantum dot structure, emission wavelength of the InAs quantum dot structure has been extended to the longest > 2.35 μm measured at 77 K. For the narrower bandgap semiconductor InAsSb quantum dots, the emission wavelength was measured at > 2.8 μm.

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Субмонослойные квантовые точки InGaAs/GaAs, выращенные методом МОС-гидридной эпитаксии

Физика и техника полупроводников ◽

10.21883/ftp.2019.08.48011.9124 ◽

2019 ◽

Vol 53 (8) ◽

pp. 1159

Author(s):

В.Я. Алешкин ◽

Н.В. Байдусь ◽

А.А. Дубинов ◽

К.Е. Кудрявцев ◽

С.М. Некоркин ◽

...

Keyword(s):

Quantum Dots ◽

Quantum Dot ◽

Room Temperature ◽

Optical Pumping ◽

Liquid Nitrogen Temperature ◽

Stimulated Emission ◽

Threshold Power ◽

Gaas Substrates ◽

Dot Density ◽

Hydride Epitaxy

AbstractThe mode of the growth of InGaAs quantum dots by MOS-hydride epitaxy on GaAs substrates without a deviation and with a deviation of 2° is selected for laser structures emitting at wavelengths above 1.2 μm at room temperature. As a result, a quantum-dot density of 4 × 10^10 cm^–2 is achieved. Stimulated emission is observed in laser structures with seven layers of quantum dots at a wavelength of 1.06 μm at liquid-nitrogen temperature. The threshold power density of optical pumping is about 5 kW/cm^2.

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Carrier kinetics in quantum dots through continuous wave photoluminescence modeling: A systematic study on a sample with surface dot density gradient

Journal of Applied Physics ◽

10.1063/1.1586953 ◽

2003 ◽

Vol 94 (3) ◽

pp. 1787-1794 ◽

Cited By ~ 14

Author(s):

F. V. de Sales ◽

J. M. R. Cruz ◽

S. W. da Silva ◽

M. A. G. Soler ◽

P. C. Morais ◽

...

Keyword(s):

Quantum Dots ◽

Density Gradient ◽

Systematic Study ◽

Continuous Wave ◽

Dot Density

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Growth and Characterization of InAs Quantum Dot Enhanced Photovoltaic Devices

MRS Proceedings ◽

10.1557/proc-1017-dd13-11 ◽

2007 ◽

Vol 1017 ◽

Cited By ~ 15

Author(s):

Seth Martin Hubbard ◽

Ryne Raffaelle ◽

Ross Robinson ◽

Christopher Bailey ◽

David Wilt ◽

...

Keyword(s):

Quantum Dots ◽

Quantum Dot ◽

Spectral Response ◽

Cell Structure ◽

Inas Quantum Dots ◽

Cell Structures ◽

Dot Density ◽

Inas Quantum Dot ◽

Iv Curves

AbstractThe growth of InAs quantum dots (QDs) by organometallic vapor phase epitaxy (OMVPE) for use in GaAs based photovoltaics devices was investigated. Growth of InAs quantum dots was optimized according to their morphology and photoluminescence using growth temperature and V/III ratio. The optimized InAs QDs had sizes near 7×40 nm with a dot density of 5(±0.5)×1010 cm-2. These optimized QDs were incorporated into GaAs based p-i-n solar cell structures. Cells with single and multiple (5x) layers of QDs were embedded in the i-region of the GaAs p-i-n cell structure. An array of 1 cm2 solar cells was fabricated on these wafers, IV curves collected under 1 sun AM0 conditions, and the spectral response measured from 300-1100 nm. The quantum efficiency for each QD cell clearly shows sub-bandgap conversion, indicating a contribution due to the QDs. Unfortunately, the overarching result of the addition of quantum dots to the baseline p-i-n GaAs cells was a decrease in efficiency. However, the addition of thin GaP strain compensating layers between the QD layers, was found to reduce this efficiency degradation and significantly enhance the subgap conversion in comparison to the un-compensated quantum dot cells.

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Charging Effect in Amorphous Silicon Quantum Dots Embedded in Silicon Nitride

MRS Proceedings ◽

10.1557/proc-638-f5.14.1 ◽

2000 ◽

Vol 638 ◽

Author(s):

Nae-Man Park ◽

Sang-Hun Jeon ◽

Hyunsang Hwang ◽

Suk-Ho Choi ◽

Seong-Ju Park

Keyword(s):

Quantum Dots ◽

Silicon Nitride ◽

Amorphous Silicon ◽

Forward Bias ◽

Chemical Vapor ◽

Silicon Quantum Dots ◽

Band Shift ◽

Capacitance Voltage ◽

Dot Density ◽

Charging Effect

AbstractCapacitance-voltage was investigated for amorphous silicon quantum dots (a-Si QDs) embedded in a silicon nitride as a function of dot size and nitride thickness. a-Sci QDs were grown by plasma enhanced chemical vapor deposition. The electron charging was decreased as the dot size was decreased. These results showed that the conduction band shift is larger than the valence band shift as the dot size decreased and, as a result, electrons are easily discharged in a-Si QDs due to the lower barrier height. For high dot-density-sample, the capacitance-voltage curves were also shifted toward the negative voltage direction when a higher forward bias was applied at forward condition due to the transfer of electrons trapped in the a-Sci QDs from the a-Sci QDs near Si substrate to those near the top metal.

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Growth and Characterization of InAs Quantum Dots on GaAsSb

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.184-185.1001 ◽

2012 ◽

Vol 184-185 ◽

pp. 1001-1005

Author(s):

Guang Yan Liu ◽

Wen Cai Wang

Keyword(s):

Quantum Dots ◽

Substrate Temperature ◽

Size Distribution ◽

Buffer Layer ◽

Lattice Mismatch ◽

Flux Ratio ◽

High Energy ◽

Inas Quantum Dots ◽

Dot Density

The growth details of strained GaAsSb layers on GaAs(001) substrates were studied by reflection high energy electron diffraction (RHEED) beam intensity oscillations as a function of both substrate temperature and Sb/As flux ratio. Both the RHEED intensity and RHEED oscillation cycles are reduced with decreasing substrate temperature and Sb/As flux ratio. InAs QDs with high dot density, small dot size and narrow size distribution have been achieved on strained GaAs / GaAsSb buffer layer. The average lateral size of dots shows a trend toward to smaller size and dots’ density shows a trend toward to higher density as the surface Sb composition increasing. The QDs with higher density and smaller size distributions at high Sb composition, indicates that the Sb plays an important role in the dot formation under this growth condition. The lattice mismatch of InAs layer with the GaAsSb buffer layer is reduced with increasing of Sb composition in the GaAsSb interlayer. This result indicates that the density, size and size distribution of self-assembled quantum dots (QDs) can be controlled through the manipulation of the Sb-mediated strain field in the lattice mismatched system.

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InNAs and GaInNAs self-assembled quantum dots and lasers grown by solid source molecular beam epitaxy

MRS Proceedings ◽

10.1557/proc-794-t3.31 ◽

2003 ◽

Vol 794 ◽

Cited By ~ 1

Author(s):

Z.Z. Sun ◽

S.F. Yoon ◽

K.C. Yew ◽

B.X. Bo

Keyword(s):

Quantum Dots ◽

Optical Properties ◽

Molecular Beam Epitaxy ◽

Quantum Dot ◽

Molecular Beam ◽

Plasma Source ◽

Nitrogen Plasma ◽

Force Microscopy ◽

Self Assembled ◽

Dot Density

ABSTRACTSelf-assembled Ga1−xInxNyAs1-y quantum dots were grown on GaAs by solid source molecular beam epitaxy (SSMBE). Introduction of N was achieved by a RF Nitrogen plasma source. Formation of quantum dots by S-K growth mode is confirmed by observation of standard 2D-3D RHEED pattern transition. Atomic force microscopy (AFM) and photoluminescence (PL) measurements were used to characterize the structure and optical properties of GaInNAs quantum dots. High GaInNAs quantum dot density (1010∼1011cm−2) was obtained for different In and N composition (0.3≤ x ≤1, y≤0.01). The effect of surface coverage on dot density, dot size, and optical properties was studied in detail. Adjusting the bandgap confinement by incorporating a GaNAs strain-reduction layer into the GaInNAs dot layer was found to extend the emission wavelength by 170nm. Room temperature pulsed operation is demonstrated for a Ga0.5In0.5N0.01As0.99 quantum dot laser emitting at ∼1.1μm.

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