scholarly journals Optical characteristics of type-II hexagonal-shaped GaSb quantum dots on GaAs synthesized using nanowire self-growth mechanism from Ga metal droplet

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Min Baik ◽  
Ji-hoon Kyhm ◽  
Hang-Kyu Kang ◽  
Kwang-Sik Jeong ◽  
Jong Su Kim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Growth Mechanism ◽  
Internal Quantum Efficiency ◽  
Band Alignment ◽  
Optical Characteristics ◽  
Droplet Epitaxy ◽  
Type Ii ◽  
Temperature Dependent ◽  
Bulk Gaas

AbstractWe report the growth mechanism and optical characteristics of type-II band-aligned GaSb quantum dots (QDs) grown on GaAs using a droplet epitaxy-driven nanowire formation mechanism with molecular beam epitaxy. Using transmission electron microscopy and scanning electron microscopy images, we confirmed that the QDs, which comprised zinc-blende crystal structures with hexagonal shapes, were successfully grown through the formation of a nanowire from a Ga droplet, with reduced strain between GaAs and GaSb. Photoluminescence (PL) peaks of GaSb capped by a GaAs layer were observed at 1.11 eV, 1.26 eV, and 1.47 eV, assigned to the QDs, a wetting-like layer (WLL), and bulk GaAs, respectively, at the measurement temperature of 14 K and excitation laser power of 30 mW. The integrated PL intensity of the QDs was significantly stronger than that of the WLL, which indicated well-grown GaSb QDs on GaAs and the generation of an interlayer exciton, as shown in the power- and temperature-dependent PL spectra, respectively. In addition, time-resolved PL data showed that the GaSb QD and GaAs layers formed a self-aligned type-II band alignment; the temperature-dependent PL data exhibited a high equivalent internal quantum efficiency of 15 ± 0.2%.

scholarly journals Optical characteristics of type-II hexagonal shaped GaSb Quantum dots on GaAs synthesized using nanowire self-growth mechanism from Ga metal droplet

2021 ◽  
Author(s):  
Min Baik ◽  
Ji-hoon Kyhm ◽  
Hang-Kyu Kang ◽  
Kwang-Sik Jeong ◽  
Jong Su Kim ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electron Microscope ◽  
Growth Mechanism ◽  
Gaas Layer ◽  
Band Alignment ◽  
Optical Characteristics ◽  
Droplet Epitaxy ◽  
Type Ii ◽  
Temperature Dependent ◽  
Bulk Gaas

Abstract We report the growth mechanism and optical characteristics of type-II band-aligned GaSb quantum dots (QDs) grown on GaAs using droplet epitaxy-driven nanowire formation mechanism in with molecular beam epitaxy (MBE). Using transmission electron microscope (TEM) and scanning electron microscope (SEM) images, we confirmed that the QDs, which comprise zinc-blende crystal structures with hexagonal shape, were successfully grown through the formation of a nanowire from a Ga droplet with less strain between GaAs and GaSb. Photoluminescence (PL) peaks of GaSb, which are capped by the GaAs layer, are observed at 1.11 eV, 1.26 eV, and 1.47 eV, assigned to the QDs, a wetting-like layer (WLL), and bulk GaAs, respectively, at the measurement temperature of 14 K and excitation laser power of 30 mW. The integrated PL intensity of the QDs is significantly stronger than the WLL, which indicates well-grown GaSb QDs on GaAs and the generation of an interlayer exciton, as shown in the power and temperature-dependent PL, respectively. In addition, Time-resolved PL (TRPL) data show that the GaSb QD and GaAs layer form a self-aligned type-II band alignment, and temperature-dependent PL data exhibit a high equivalent internal quantum efficiency of 15+/-0.2%.

SPACE-CHARGE SPECTROSCOPY OF ELECTRONIC STATES IN Ge/Si QUANTUM DOTS WITH TYPE-II BAND ALIGNMENT

2007 ◽  
Vol 06 (05) ◽  
pp. 353-356
Author(s):  
A. I. YAKIMOV ◽  
A. V. DVURECHENSKII ◽  
A. I. NIKIFOROV ◽  
A. A. BLOSHKIN
Keyword(s):  
Quantum Dots ◽  
Electronic Structure ◽  
Binding Energy ◽  
Space Charge ◽  
Tensile Strain ◽  
Electronic States ◽  
Band Alignment ◽  
Type Ii ◽  
Electron Confinement ◽  
Si Quantum Dots

Space-charge spectroscopy was employed to study electronic structure in a stack of four layers of Ge quantum dots coherently embedded in an n-type Si (001) matrix. Evidence for an electron confinement in the vicinity of Ge dots was found. From the frequency-dependent measurements the electron binding energy was determined to be ~50 meV, which is consistent with the results of numerical analysis. The data are explained by a modification of the conduction band alignment induced by inhomogeneous tensile strain in Si around the buried Ge dots.

Band Alignment Tailoring of InAs1−xSbx/GaAs Quantum Dots: Control of Type I to Type II Transition

Nano Letters ◽  
2010 ◽  
Vol 10 (8) ◽  
pp. 3052-3056 ◽  
Author(s):  
J. He ◽  
C. J. Reyner ◽  
B. L. Liang ◽  
K. Nunna ◽  
D. L. Huffaker ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Band Alignment ◽  
Type I ◽  
Type Ii

Formation and Optical Characteristics of Type-II Strain-Relieved GaSb/GaAs Quantum Dots by Using an Interfacial Misfit Growth Mode

2009 ◽  
Vol 8 (2) ◽  
pp. 269-274 ◽  
Author(s):  
J. Tatebayashi ◽  
Baolai Liang ◽  
D.A. Bussian ◽  
H. Htoon ◽  
Shenghong Huang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Growth Mode ◽  
Optical Characteristics ◽  
Type Ii

scholarly journals A Comparative Study on Optical Characteristics of InGaAsP QW Heterostructures of Type-I and Type-II Band Alignments

2018 ◽  
Vol 7 (1) ◽  
pp. 35-41
Author(s):  
Garima Bhardwaj ◽  
Sandhya K. ◽  
Richa Dolia ◽  
M. Abu-Samak ◽  
Shalendra Kumar ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Region ◽  
High Gain ◽  
Band Alignment ◽  
Optical Characteristics ◽  
Hamiltonian Matrix ◽  
Type I ◽  
Type Ii ◽  
Te Mode ◽  
Band Alignments

In this paper, we have configured InGaAsP QW (quantum well) heterostructures of type-I and type-II band alignments and simulated their optical characteristics by solving 6 x 6 Kohn-Luttinger Hamiltonian Matrix. According to the simulation results, the InGaAsP QW heterostructure of type-I band alignment has been found to show peak optical gain (TE mode) of the order of~3600/cm at the transition wavelength~1.40 µm; while of type-II band alignment has achieved the peak gain (TE mode) of the order of~7800/cm at the wavelength of~1.85 µm (eye safe region). Thus, both of the heterostructures can be utilized in designing of opto-or photonic devices for the emission of radiations in NIR (near infrared region) but form the high gain point of view, the InGaAsP of type-II band alignment can be more preferred.

Optical characterization of type-I to type-II band alignment transition in GaAs/AlxGa1−xAs quantum rings grown by droplet epitaxy

2017 ◽  
Vol 50 (32) ◽  
pp. 32LT01 ◽  
Author(s):  
Linlin Su ◽  
Ying Wang ◽  
Qinglin Guo ◽  
Xiaowei Li ◽  
Shufang Wang ◽  
...  
Keyword(s):  
Optical Characterization ◽  
Band Alignment ◽  
Droplet Epitaxy ◽  
Type I ◽  
Type Ii ◽  
Quantum Rings

GaAs Quantum Dots with Type-II Band Alignment

2011 ◽  
Author(s):  
T. Kuroda ◽  
T. Mano ◽  
M. Abbarchi ◽  
K. Sakoda ◽  
Jisoon Ihm ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Band Alignment ◽  
Type Ii

Type-II GaSb/GaAs Nanostructures Grown by Droplet Epitaxy with Various Ga Amounts

2015 ◽  
Vol 1131 ◽  
pp. 60-63 ◽  
Author(s):  
Maetee Kunrugsa ◽  
Somsak Panyakeow ◽  
Somchai Ratanathammaphan
Keyword(s):  
Quantum Dots ◽  
Atomic Force Microscopy ◽  
Optical Properties ◽  
Droplet Epitaxy ◽  
Formation Mechanisms ◽  
Type Ii ◽  
Quantum Rings ◽  
Force Microscopy ◽  
Atomic Force

We study the GaSb/GaAs nanostructures (NSs) grown by droplet epitaxy technique with various Ga amounts. Ga amount deposited on the GaAs (001) substrate was varied between 3-5 ML to form the different size and density of liquid Ga droplets. The Sb flux was subsequently irradiated to crystallize the droplets. Morphology of GaSb NSs was investigated by atomic force microscopy (AFM). Quantum rings were obtained after crystallizing 3-ML Ga droplets, whereas some kind of quantum dots were formed after crystallizing 4-and 5-ML Ga droplets. The formation mechanisms leading to the different structure are discussed. The photoluminescence (PL) measurement was performed to examine the optical properties of GaSb/GaAs NSs.

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