VLS Growth of Position-controlled InP Nanowires and Formation of Radial Heterostructures on Mask-patterned InP Substrates

2014 ◽  
Vol 1659 ◽  
pp. 181-186 ◽  
Author(s):  
Kenichi Kawaguchi ◽  
Hisao Sudo ◽  
Manabu Matsuda ◽  
Mitsuru Ekawa ◽  
Tsuyoshi Yamamoto ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Room Temperature ◽  
Wavelength Region ◽  
Two Dimensional ◽  
Au Catalyst ◽  
Vapor Liquid Solid ◽  
Vls Growth ◽  
Hcl Gas ◽  
Inp Substrates ◽  
Anomalous Growth

ABSTRACTPosition-controlled InP nanowires (NWs) with separations of 10-100 μm were grown by the vapor-liquid-solid (VLS) method using Au-deposited SiO2-mask-patterned InP substrates. Excess indium species diffused from the large mask region formed plural tilted NW-like structures from single openings in addition to the vertical VLS NWs formed by Au catalyst. The introduction of HCl gas during the NW growth was found to efficiently suppress the tilted NW-like structures. Vertical InP NWs without anomalous growth were successfully formed by controlling the HCl flow rate. Moreover, single InP/InAsP/InP quantum wells (QWs) with wurtzite crystal phase structure were epitaxially grown on the sidewall of the position-controlled InP NWs, and two-dimensional arrayed patterns of photoluminescence (PL) coming from the radial QWs were clearly observed in the 1.3-μm wavelength region at room temperature.

Influence of Growth Conditions on the Modulation Mechanism of Photoreflectance Spectra of Single InGaAs/InAlAs Quantum Wells

1993 ◽  
Vol 324 ◽  
Author(s):  
Y. Baltagi ◽  
C. Bru ◽  
T. Benyatrou ◽  
M.A. Garcia-Perez ◽  
G. Guillot ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Room Temperature ◽  
Growth Conditions ◽  
Surface Barrier ◽  
Single Quantum ◽  
Interface Defects ◽  
Growth Interruption ◽  
Different Temperatures ◽  
Inp Substrates ◽  
Pump Laser Beam

AbstractUsing Photoreflectance (PR) measurements, we have investigated In0.53Ga0.47As single quantum wells (SQW) with In0.52Al0.48As barriers grown by MBE on InP substrates. Unusual lineshapes of PR spectra are observed for the fundamental transition in some of the SQW. This phenomenon is shown to be independent on the widths of both the SQW (5nm or 10nm) and the surface barrier layer (between 65nm and 300nm). PR spectra are recorded at different temperatures and in different samples, as well as with a secondary pump laser beam. From these measurements, it is concluded that interface defects exist in the SQW grown at 525°C without growth interruption. Such defects are clearly evidenced in room temperature PR experiments and confirmed by PL measurements.

scholarly journals Two-dimensional hybrid perovskites sustaining strong polariton interactions at room temperature

2019 ◽  
Vol 5 (5) ◽  
pp. eaav9967 ◽  
Author(s):  
A. Fieramosca ◽  
L. Polimeno ◽  
V. Ardizzone ◽  
L. De Marco ◽  
M. Pugliese ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Degrees Of Freedom ◽  
Room Temperature ◽  
Optical Cavity ◽  
Oscillator Strengths ◽  
Layered Perovskite ◽  
Two Dimensional ◽  
Coherent Coupling ◽  
Highly Nonlinear ◽  
Order Of Magnitude

Polaritonic devices exploit the coherent coupling between excitonic and photonic degrees of freedom to perform highly nonlinear operations with low input powers. Most of the current results exploit excitons in epitaxially grown quantum wells and require low-temperature operation, while viable alternatives have yet to be found at room temperature. We show that large single-crystal flakes of two-dimensional layered perovskite are able to sustain strong polariton nonlinearities at room temperature without the need to be embedded in an optical cavity formed by highly reflecting mirrors. In particular, exciton-exciton interaction energies are shown to be spin dependent, remarkably similar to the ones known for inorganic quantum wells at cryogenic temperatures, and more than one order of magnitude larger than alternative room temperature polariton devices reported so far. Because of their easy fabrication, large dipolar oscillator strengths, and strong nonlinearities, these materials pave the way for realization of polariton devices at room temperature.

Improvement in Uniformity of Type-II p-GaAsSb/n-InAs Nanowires on GaAs Substrates by the Insertion of GaAs Segments in Position-controlled VLS Method

MRS Advances ◽  
2019 ◽  
Vol 4 (5-6) ◽  
pp. 331-336
Author(s):  
Kenichi Kawaguchi ◽  
Tsuyoshi Takahashi ◽  
Naoya Okamoto ◽  
Masaru Sato ◽  
Michihiko Suhara
Keyword(s):  
Gaas Substrate ◽  
High Performance ◽  
Growth Strategy ◽  
Type Ii ◽  
Tunnel Diodes ◽  
Au Catalyst ◽  
Vapor Liquid Solid ◽  
Gaas Substrates ◽  
Inas Nanowires ◽  
Anomalous Growth

AbstractTo improve the uniformity of type-II GaAsSb/InAs nanowires (NWs) grown on GaAs substrate using the position-controlled vapor-liquid-solid (VLS) method, the insertion of GaAs NW segments was investigated. In conventional InAs NWs grown directly on patterned GaAs substrate at 430°C, anomalous growth occurred in some pattern holes, and the proportion of holes having anomalous growth was in particular pronounced when a large Au catalyst diameter (80 nm) was employed, which indicates that the strain coming from the lattice-mismatched system affected the NW growth. With the insertion of GaAs segments, the yield of vertical NWs drastically improved for all pattern conditions. The uniformity of NWs was maintained after the growth of p-GaAsSb segments, and well-organized, two-dimensional arrays of type-II GaAsSb/InAs diode NWs were obtained. Moreover, the formation of p-n junctions at the GaAsSb/InAs interface was clearly observed using scanning capacitive microscopy. These results show that the investigated growth strategy is promising for the development of high-performance NW tunnel diodes.

Room-temperature Electroluminescence of Radial p-i-n InP Nanowires with InAsP Quantum Wells in the 1.5-μm Wavelength Region

2014 ◽  
Author(s):  
K. Kawaguchi ◽  
H. Sudo ◽  
M. Matsuda ◽  
M. Ekawa ◽  
T. Yamamoto ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Room Temperature ◽  
Wavelength Region

Optical Properties of Amorphous and Nanostructure Si/SiO2 Quantum Wells

2013 ◽  
Vol 26 ◽  
pp. 59-62 ◽  
Author(s):  
Toshio Takeuchi ◽  
Minoru Kondo ◽  
Miki Fujuta ◽  
Atsushi Kawaharazuka ◽  
Yoshiji Horikoshi
Keyword(s):  
Quantum Wells ◽  
Room Temperature ◽  
Layer Structure ◽  
Wavelength Region ◽  
Optical Transmittance ◽  
Energy Dependency ◽  
Quantum Confinement Effects ◽  
Absorption Edge Energy ◽  
Atomic Precision ◽  
Amorphous Si

Amorphous Si/SiO2quantum wells have been obtained at room temperature with atomic precision using magnetron sputtering. The Si/SiO2layer structure induces the higher optical transmittance at the visible wavelength region with increasing layer numbers. The tentative absorption coefficients are evaluated for integrated Si thicknesses. The absorption edge energy dependency on Si layer thickness E0= 1.61 + 0.75d-2is in accordance with effective mass theory for thicknesses 0.5 < d < 6nm. Quantum confinement effects of the Si/SiO2nanostructure layer are confirmed from optical transmittance and reflectance spectra.

scholarly journals Room temperature quantum spin Hall states in two-dimensional crystals composed of pentagonal rings and their quantum wells

2016 ◽  
Vol 8 (4) ◽  
pp. e264-e264 ◽  
Author(s):  
Yandong Ma ◽  
Liangzhi Kou ◽  
Xiao Li ◽  
Ying Dai ◽  
Thomas Heine
Keyword(s):  
Quantum Wells ◽  
Room Temperature ◽  
Quantum Spin ◽  
Two Dimensional ◽  
Hall States ◽  
Quantum Spin Hall

VLS Growth of Si nanowhiskers on a H-terminated Si{111} surface

1998 ◽  
Vol 536 ◽  
Author(s):  
N. Ozaki ◽  
Y. Ohno ◽  
S. Takeda ◽  
M. Hirata
Keyword(s):  
High Pressure ◽  
Growth Condition ◽  
Growth Mechanism ◽  
Quantum Confinement ◽  
Critical Value ◽  
Extended Defects ◽  
Vapor Liquid Solid ◽  
Minimum Diameter ◽  
Vls Growth ◽  
Vapor Liquid

AbstractWe have grown Si nanowhiskers on a Si{1111} surface via the vapor-liquid-solid (VLS) mechanism. The minimum diameter of the crystalline is 3nm and is close to the critical value for the effect of quantum confinement. We have found that many whiskers grow epitaxially or non-epitaxially on the substrate along the 〈112〉 direction as well as the 〈111〉 direction.In our growth procedure, we first deposited gold on a H-terminated Si{111} surface and prepared the molten catalysts of Au and Si at 500°C. Under the flow of high pressure silane gas, we have succeeded in producing the nanowhiskers without any extended defects. We present the details of the growth condition and discuss the growth mechanism of the nanowhiskers extending along the 〈112〉 direction.

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