The Investigation of Porous AlXGa1-XN Layers on Si (111) Substrate with GaN/AlN as Buffer Layer

2011 ◽  
Vol 364 ◽  
pp. 164-168
Author(s):  
Yushamdan Yusof ◽  
Mohd Zaki Mohd Yusoff ◽  
Mahmood Ainorkhilah ◽  
Hassan Zainuriah ◽  
Abu Hassan Haslan ◽  
...  
Keyword(s):  
Optical Properties ◽  
Molecular Beam Epitaxy ◽  
Buffer Layer ◽  
Molecular Beam ◽  
Lattice Mismatch ◽  
Electrochemical Etching ◽  
High Quality ◽  
Pl Spectra ◽  
Anisotropic Structures ◽  
Uv Lamp

High quality undoped AlxGa1-xN with high Ga composition was grown on Si (111) substrate, using GaN/AlN as the buffer layer, by plasma-assisted molecular beam epitaxy (PAMBE). The present work reports on the photoluminescence (PL) studies of porous AlxGa1-xN prepared by ultraviolet (UV) assisted electrochemical etching in a solution of 2 % concentration of KOH electrolyte under illumination of an UV lamp with 500 W power for 30 min. The optical properties of porous AlxGa1-xN sample was compared to the corresponding as-grown GaN. PL studies suggested that the porosity was capable of improving the lattice mismatch induced strain. Porosity induced PL intensity enhancement was found in nanoporous sample. The resulting nanoporous AlxGa1-xN display red-shifted PL spectra compared to the as-grown AlxGa1-xN. Appearance of the red-shifted emission is correlated with the development of highly anisotropic structures in the morphology.

Molecular beam epitaxy of high-quality CuI thin films on a low temperature grown buffer layer

2020 ◽  
Vol 116 (19) ◽  
pp. 192105 ◽  
Author(s):  
S. Inagaki ◽  
M. Nakamura ◽  
N. Aizawa ◽  
L. C. Peng ◽  
X. Z. Yu ◽  
...  
Keyword(s):  
Thin Films ◽  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Buffer Layer ◽  
Molecular Beam ◽  
High Quality

Photovoltaic effect of ferroelectric Pb(Zr0.52,Ti0.48)O3 deposited on SrTiO3 buffered n-GaAs by laser molecular beam epitaxy

2017 ◽  
Vol 10 (04) ◽  
pp. 1750036 ◽  
Author(s):  
Yunxia Zhou ◽  
Jun Zhu ◽  
Xingpeng Liu ◽  
Zhipeng Wu
Keyword(s):  
Thin Film ◽  
Molecular Beam Epitaxy ◽  
Buffer Layer ◽  
Molecular Beam ◽  
Lattice Mismatch ◽  
Photovoltaic Effect ◽  
Short Circuit ◽  
High Energy ◽  
Text Type ◽  
Laser Molecular Beam Epitaxy

Ferroelectric Pb(Zr[Formula: see text],Ti[Formula: see text]O3(PZT) thin film was grown on [Formula: see text]-type GaAs (001) substrate with SrTiO3 (STO) buffer layer by laser molecular beam epitaxy (L-MBE). The epitaxial process of the STO was in situ monitored by reflection high-energy electron diffraction (RHEED). The crystallographical growth orientation relationship was revealed to be (002) [Formula: see text] PZT//(002) [Formula: see text] STO//(001) [Formula: see text] GaAs by RHEED and X-ray diffraction (XRD). It was found that a small lattice mismatch between PZT and GaAs with a 45[Formula: see text] in-plane rotation relationship can be formed by inserting of a buffer layer STO. Besides, the enhanced electrical properties of the heterostructure were obtained with the short-circuit photocurrent increased to 52[Formula: see text]mA/cm2 and the better power conversation efficiency increased by 20% under AM1.5[Formula: see text]G (100[Formula: see text]mW/cm[Formula: see text] illumination. The work could provide a way for the application of this kind of heterostructure with high photocurrent response in optoelectronic thin film devices.

The Structural and Optical Properties of Be-Doped GaAs Grown by MBE

2015 ◽  
Vol 1118 ◽  
pp. 111-117
Author(s):  
Hui Min Jia ◽  
Ji Long Tang ◽  
Liang Chang ◽  
Dan Fang ◽  
Xuan Fang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Doping Concentration ◽  
Molecular Beam ◽  
Hall Measurement ◽  
Temperature Dependent ◽  
Structural And Optical Properties ◽  
Pl Spectra

In this paper, Be-doped GaAs were grown by molecular beam epitaxy (MBE), by changing Be resource temperature, we obtained different doping concentration GaAs samples. The morphologies and electrics properties of the samples were investigated by AFM and Hall measurement. Especially, in low temperature and temperature dependent PL spectra, the Be acceptor related emission were recognized, with the doping concentration increasing, the Be acceptor related emission enhanced too.

Molecular beam epitaxy growth of high quality p-doped SnS van der Waals epitaxy on a graphene buffer layer

2012 ◽  
Vol 111 (9) ◽  
pp. 093520 ◽  
Author(s):  
W. Wang ◽  
K. K. Leung ◽  
W. K. Fong ◽  
S. F. Wang ◽  
Y. Y. Hui ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Buffer Layer ◽  
Molecular Beam ◽  
Van Der Waals ◽  
Molecular Beam Epitaxy Growth ◽  
High Quality

scholarly journals Исследование влияния переходного слоя нанопористого кремния на атомное и электронное строение, а также оптические свойства гетероструктур A-=SUP=-III-=/SUP=-N/por-Si, выращенных методом плазменно-активированной молекулярно-пучковой эпитаксии

2019 ◽  
Vol 53 (7) ◽  
pp. 1010
Author(s):  
П.В. Середин ◽  
А.С. Леньшин ◽  
Д.С. Золотухин ◽  
Д.Л. Голощапов ◽  
А.М. Мизеров ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Molecular Beam Epitaxy ◽  
Buffer Layer ◽  
Structural Properties ◽  
Molecular Beam ◽  
Diameter Distribution ◽  
Structure Morphology ◽  
Nanoporous Si ◽  
Pl Intensity

This paper reports on influence of the nanoporous Si buffer layer on morphological, physical and structural properties of the InxGa1-xN layer with nanocolumnar morphology of the surface, grown by plasma assisted molecular beam epitaxy on the traditional Si(111) substrates. By means of various structural and spectroscopy methods electronic structure, morphology of the surface and optical properties of grown heterostructures was studied. We showed that usage of por-Si ad-layer helps to achieve more isotropic InGaN nanocolumns diameter distribution as well as to increase PL intensity up to 25%.

Microstructures of GaN films deposited on (001) and (111) Si substrates using electron cyclotron resonance assisted-molecular beam epitaxy

1994 ◽  
Vol 9 (9) ◽  
pp. 2370-2378 ◽  
Author(s):  
S.N. Basu ◽  
T. Lei ◽  
T.D. Moustakas
Keyword(s):  
Molecular Beam Epitaxy ◽  
Buffer Layer ◽  
Cyclotron Resonance ◽  
Molecular Beam ◽  
Electron Cyclotron Resonance ◽  
Lattice Mismatch ◽  
Defect Density ◽  
Electron Cyclotron ◽  
Si Substrates ◽  
Zinc Blende

The microstructures of GaN films, grown on (001) and (111) Si substrates by a two-step method using Electron Cyclotron Resonance assisted-Molecular Beam Epitaxy (ECR-MBE), were studied by electron microscopy techniques. Films grown on (001) Si had a predominantly zinc-blende structure. The GaN buffer layer, grown in the first deposition step, accommodated the 17% lattice mismatch between the film and substrate by a combination of misoriented domains and misfit dislocations. Beyond the buffer layer, the film consisted of highly oriented domains separated by inversion domain boundaries, with a substantial decrease in the defect density away from the interface. The majority of defects in the film were stacking faults, microtwins, and localized regions having the wurtzite structure. The structure of the GaN films grown on (111) Si was found to be primarily wurtzite, with a substantial fraction of twinned zinc-blende phase. Occasional wurtzite grains, misoriented by a 30°twist along the [0001] axis, were also observed. A substantial diffusion of Si was seen in films grown on both substrates.

Excitons bound to structural defects in GaN

2001 ◽  
Vol 693 ◽  
Author(s):  
M. A. Reshchikov ◽  
D. Huang ◽  
F. Yun ◽  
H. Morkoç ◽  
R. J. Molnar ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Room Temperature ◽  
Molecular Beam ◽  
Structural Defects ◽  
Excitation Density ◽  
High Quality ◽  
Pl Spectra ◽  
Sapphire Substrates ◽  
Uv Illumination ◽  
Increasing Temperature

AbstractWe analyzed the photoluminescence (PL) spectra of undoped GaN films grown by molecular beam epitaxy on sapphire substrates. While the PL spectra from high-quality samples contain free and bound exciton peaks only, the spectra from some samples involve sharp unidentified peaks in the energy range of 3.0 – 3.45 eV, specifically at 3.21, 3.32, 3.36, and 3.42 eV. We attribute these peaks to excitons bound to defects because of the linear and sometimes superlinear increase in their intensity with excitation density without saturation up to 100 W/cm2. With increasing temperature these peaks quench in a well-known fashion similar to that for excitons. In order to relate the observed peaks to the structural defects, we etched selected samples in hot H3PO4 acid or, alternatively, with photo-electrochemical (PEC) etching at room temperature in the presence of UV-illumination in a dilute KOH solution. In the former case the dislocations were etched leaving etched pits on the surface, while in the latter case the dislocations remained unetched due to a deficit of photogenerated holes at dislocation sites. We found that the 3.42 eV peak disappeared after both hot wet and PEC etching suggesting that the associated defect is at the GaN surface. Peaks at 3.21 and 3.36 eV could be enhanced greatly by PEC etching, which were correlated to bulk dislocations.

Growth and Characterization of InxGa1−xP(x≤0.38) on GaP(1OO) with a Linearly Graded Buffer Layer by Gas-Source Molecular Beam Epitaxy

1992 ◽  
Vol 281 ◽  
Author(s):  
T. P. Chin ◽  
J. C. P. Chang ◽  
K. L. Kavanagh ◽  
C. W. Tu ◽  
P. D. Kirchner ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Buffer Layer ◽  
Molecular Beam ◽  
Lattice Mismatch ◽  
High Energy ◽  
Threading Dislocation ◽  
Dislocation Loops ◽  
Double Crystal ◽  
X Ray ◽  
Gas Source

ABSTRACTInxGa1−xP(x>0.27) grown on a GaP substrate has a large direct-bandgap, which is suitable for yellow light emission on a transparent substrate. Because of the large lattice mismatch, usually a thick (10–20 μm) graded buffer layer was required to reduce the threading dislocation density. In this work we report that a thin (1.2 μm for x≃0.35), linearly graded buffer layer can filter out dislocations effectively. The structures were grown by gas-source molecular beam epitaxy. Reflection high-energy electron diffraction (RHEED) intensity oscillations and X-ray double-crystal diffraction were used to control and determine the composition, respectively. Threading dislocations are well confined in the buffer layer, as shown under transmission electron microscopy. Dislocation loops injected into the substrate were observed, similar to those observed in the Six Ge1−x/Si system. X-ray analysis also shows that the 3% mismatched buffer layer is fully relaxed. This relaxed buffer layer then can serve as a substrate for further growth. Homojunction and heterojunction light emitting diodes were fabricated to demonstrate the material quality.

Achieving high-quality In0.3Ga0.7As films on GaAs substrates by low-temperature molecular beam epitaxy

CrystEngComm ◽  
2014 ◽  
Vol 16 (47) ◽  
pp. 10774-10779 ◽  
Author(s):  
Fangliang Gao ◽  
Lei Wen ◽  
Jingling Li ◽  
Yunfang Guan ◽  
Shuguang Zhang ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Buffer Layer ◽  
Gaas Substrate ◽  
Molecular Beam ◽  
High Quality ◽  
Gaas Substrates

The effects of the thickness of the large-mismatched amorphous In0.6Ga0.4As buffer layer on the In0.3Ga0.7As epi-films grown on the GaAs substrate have been systematically investigated.

Sign in / Sign up

Export Citation Format

Share Document