scholarly journals Excitation power dependence of photoluminescence spectra of GaSb type-II quantum dots in GaAs grown by droplet epitaxy

AIP Advances ◽  
2016 ◽  
Vol 6 (4) ◽  
pp. 045312 ◽  
Author(s):  
T. Kawazu ◽  
T. Noda ◽  
Y. Sakuma ◽  
H. Sakaki
Keyword(s):  
Quantum Dots ◽  
Excitation Power ◽  
Droplet Epitaxy ◽  
Type Ii ◽  
Power Dependence ◽  
Photoluminescence Spectra

Excitation Power Dependence of Photoluminescence in CIB and FIB Implanted Superlattices

1991 ◽  
Vol 240 ◽  
Author(s):  
A. G. Choo ◽  
H. E. Jackson ◽  
P. Chen ◽  
A. J. Steckl ◽  
V. Gupta ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Peak Position ◽  
Excitation Power ◽  
Excitation Intensity ◽  
Power Dependence ◽  
Photoluminescence Spectra ◽  
Multiple Scan ◽  
Donor Acceptor ◽  
Low Temperature Photoluminescence

ABSTRACTLow temperature photoluminescence spectra have been used to characterize conventional ion beam (CIB) and focused ion beam (FIB) implanted superlattices. The excitation dependence of the single scan FIB is found to be significantly different from CIB and multiple scan FIB implantations which are similar. The peak position of the donor-acceptor transition is observed to change to higher energies significantly slower with excitation intensity for the single scan FIB case when compared to the multiple scan FIB and CIB cases. Simple models to describe these effects are briefly discussed.

Excitation Power Dependence Of Photoluminescence From GaAs Quantum Dot Prepared By Droplet Epitaxy Method

2011 ◽  
Author(s):  
H. Y. Choi ◽  
D. Y. Kim ◽  
M. Y. Cho ◽  
G. S. Kim ◽  
S. M. Jeon ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Excitation Power ◽  
Droplet Epitaxy ◽  
Power Dependence ◽  
Gaas Quantum Dot

DYNAMICS OF SPATIALLY INDIRECT EXCITONS IN SEMICONDUCTOR HETEROSTRUCTURES IN MAGNETIC FIELDS

2007 ◽  
Vol 21 (08n09) ◽  
pp. 1574-1578
Author(s):  
KAZUHITO UCHIDA ◽  
NOBORU MIURA ◽  
YASUHIRO SHIRAKI
Keyword(s):  
Magnetic Fields ◽  
Quantum Wells ◽  
Excitation Power ◽  
Semiconductor Heterostructures ◽  
Type Ii ◽  
Power Dependence ◽  
Indirect Excitons ◽  
Peak Energy ◽  
Excitation Laser ◽  
The Magnetic Field

Magnetophotoluminescence from spatially separated excitons in type-II semiconductor heterostructures, GaP/AlP neighboring confinement structures (NCSs) have been investigated. The sample studied consists of adjacent GaP and AlP quantum wells sandwiched between AlGaP barriers. The excitation power dependence and the well thickness dependence of the exciton PL are studied in magnetic fields applied perpendicular to the heterointerfaces. Compared to the thinner NCS, the magneto-PL of the wider NCS is strongly modified by the excitation power; the magnetic field dependence of the PL peak energy clearly changes from the anomalous red-shifts into the diamagnetic shifts with increasing excitation laser power.

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.

EFFECTS OF ANTIMONY FLUX ON MORPHOLOGY AND PHOTOLUMINESCENCE SPECTRA OF GaSb QUANTUM DOTS FORMED ON GaAs BY DROPLET EPITAXY

2010 ◽  
Vol 19 (04) ◽  
pp. 819-826 ◽  
Author(s):  
T. KAWAZU ◽  
T. NODA ◽  
T. MANO ◽  
M. JO ◽  
H. SAKAKI
Keyword(s):  
Quantum Dots ◽  
Microscope Study ◽  
Molecular Beam ◽  
Broad Peak ◽  
Droplet Epitaxy ◽  
Wetting Layer ◽  
Photoluminescence Spectra ◽  
Coalescence Process ◽  
Strong Luminescence

We investigated effects of the antimony flux on GaSb quantum dots (QDs) formed by droplet epitaxy. Ga droplets were first formed on GaAs and exposed to Sb4 molecular beam at 200 °C, where the flux PSb of Sb beam was varied from 2.4 to 12.8 × 10-7 Torr. The samples were then annealed for 2 minutes under the Sb flux. An atomic microscope study showed that the diameter of GaSb QDs increases and the density decreases, as the Sb flux PSb is increased. This indicates that the coalescence process of GaSb QDs occurs and is accelerated by the increase of the Sb flux. In a photoluminescence (PL) study, we observed a broad peak of GaSb QDs in all samples, while a strong luminescence of a wetting layer (WL)-like structure was found only in the samples prepared with the high Sb flux. This suggests that the PL of WL is controllable by adjusting the flux PSb of Sb beam.

GaSb/GaAs type-II quantum dots grown by droplet epitaxy

2009 ◽  
Vol 20 (45) ◽  
pp. 455604 ◽  
Author(s):  
Baolai Liang ◽  
Andrew Lin ◽  
Nicola Pavarelli ◽  
Charles Reyner ◽  
Jun Tatebayashi ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Droplet Epitaxy ◽  
Type Ii

scholarly journals Phonon Characterization, Structural and Optical Properties of Type-II CdSe/CdTe core/shell and Type-II/type-I CdSe/CdTe/ZnS core/shell/shell Quantum Dots

2020 ◽  
Vol 36 (3) ◽  
Author(s):  
Nguyen Xuan Ca ◽  
Nguyen Thi Hien
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Excitation Power ◽  
Cubic Phase ◽  
Core Shell ◽  
Type I ◽  
Type Ii ◽  
X Ray Diffraction ◽  
Cdte Core ◽  
Observation Results

The CdSe, type-II CdSe/CdTe core/shell and type-II/type-I CdSe/CdTe/ZnS core/shell/shell  quantum dots (QDs) were successfully synthesized in a noncoordinating solvent. The phonon characterizations, optical properties and structures of the synthesized QDs were characterized by Raman scattering (RS) spectra, photoluminescence (PL) spectroscopy, PL-decay lifetime, absorption spectroscopy (Abs), and X-ray diffraction (XRD). The growth of QDs was monitored by using RS, which demonstrated the formation of correct of the core/shell and core/shell/shell structures. Observation results from XRD reveal that all QDs crystallize in the cubic phase with zinc-blende structure. The typical characteristics of spatially indirect recombination for type-II QDs were observed through Abs and PL spectroscopy. The ZnS shell significantly enhanced the PL quantum yeild (QY), the optical durability, the chemical stability and separating CdSe/CdTe QDs from the surroundings. The effect of excitation power on the PL properties of the CdSe core,  CdSe/CdTe and CdSe/CdTe/ZnS QDs has been investigated.

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%.

Sign in / Sign up

Export Citation Format

Share Document