scholarly journals X-Ray Diffraction Analyses of ZnO and (Zn, Mg)O Single Crystalline Films Epitaxially Grown on a-Plane Sapphire Substrates

2007 ◽  
Vol 56 (3) ◽  
pp. 223-228 ◽  
Author(s):  
Katsuhiko INABA ◽  
Kazuto KOIKE ◽  
Shigehiko SASA ◽  
Masataka INOUE ◽  
Mitsuaki YANO
Keyword(s):  
X Ray Diffraction ◽  
Single Crystalline ◽  
X Ray ◽  
Sapphire Substrates ◽  
Crystalline Films

scholarly journals Large Area Free-Standing Single Crystalline Films of p-Quinquephenyl: Growth, Structure and Photoluminescence Properties

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 363
Author(s):  
Valery A. Postnikov ◽  
Nataliya I. Sorokina ◽  
Maria S. Lyasnikova ◽  
Artem A. Kulishov ◽  
Alexey E. Voloshin ◽  
...  
Keyword(s):  
Photoluminescence Spectra ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Large Area ◽  
Free Standing ◽  
Slow Cooling ◽  
Single Crystalline ◽  
X Ray ◽  
Growth Structure ◽  
Crystalline Films

Studies of the growth of large-area free-standing single-crystalline films of p-quinquephenyl are presented. High-quality crystals were grown by slow cooling of a hot chlorobenzene solution. Worse quality large-area free-standing single crystals of p-quinquephenyl were also grown by using physical vapor transport and used for comparison. The crystal structure of p-quinquephenyl at 293 K and 85 K was refined by single-crystal X-ray diffraction. The optical absorption and photoluminescence spectra of solutions and crystalline films were obtained and analyzed; a positive solvatochromic effect was detected.

Direct observation of intrinsic piezoelectricity of Pb(Zr,Ti)O3 by time-resolved x-ray diffraction measurement using single-crystalline films

2014 ◽  
Vol 105 (1) ◽  
pp. 012905 ◽  
Author(s):  
Takashi Fujisawa ◽  
Yoshitaka Ehara ◽  
Shintaro Yasui ◽  
Takafumi Kamo ◽  
Tomoaki Yamada ◽  
...  
Keyword(s):  
Direct Observation ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
Single Crystalline ◽  
X Ray ◽  
Crystalline Films

Single Crystalline SnO2:In Films Prepared on Sapphire by MOCVD

2009 ◽  
Vol 79-82 ◽  
pp. 759-762 ◽  
Author(s):  
Zhen Guo Song ◽  
Feng Ji ◽  
Jin Ma ◽  
Ti Ning ◽  
Xu An Pei ◽  
...  
Keyword(s):  
Tin Oxide ◽  
Hall Mobility ◽  
Photoelectron Spectroscopy ◽  
Film Surface ◽  
Atomic Ratio ◽  
Hrtem Image ◽  
Single Crystalline ◽  
X Ray ◽  
Sapphire Substrates ◽  
Crystalline Films

1-12% {atomic ratio of In/(In+Sn)} indium-doped tin oxide (SnO2:In) films were successfully prepared on sapphire substrates by MOCVD method. HRTEM image showed that the obtained films were single crystalline films. The X-ray photoelectron spectroscopy showed the existence of non-stoichiometric oxide on the film surface. The Hall mobility and carrier concentration of the SnO2:In films varied with the In content increasing.

scholarly journals Chemical vapor deposition of sp2-boron nitride films on Al2O3 (0001), (11𝟐0), (1𝟏02) and (10𝟏0) substrates

2021 ◽  
Author(s):  
Sachin Sharma ◽  
Laurent Souqui ◽  
Henrik Pedersen ◽  
Hans Högberg
Keyword(s):  
Chemical Vapor Deposition ◽  
Boron Nitride ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sapphire Substrates ◽  
Crystalline Films ◽  
Boron Nitride Films ◽  
Potential Use

Thin films of boron nitride in its sp2-hybridized form (sp2-BN) have potential use in UV-devices and dielectrics. Here, we explore chemical vapor deposition (CVD) of sp2-BN on various cuts of sapphire; Al2O3(112̅0), Al2O3(11̅02), Al2O3(11̅00) and Al2O3 (0001) using two CVD processes with different boron precursors; triethylborane (TEB) and trimethylborane (TMB). Fourier transform infrared spectroscopy (FTIR) showed that sp2-BN grows on all the sapphire substrates, using X-ray diffraction (XRD), 2θ/ω diffractograms showed that only Al2O3(112̅0) and Al2O3(0001) renders crystalline films and using phi(ɸ)-scans the growth of rhombohedral polytype (r-BN) films on these substrates is confirmed. These films are found to be epitaxially grown on an AlN interlayer with a higher crystalline quality for the films grown on the Al2O3(112̅0) substrate which is determined using omega(ω)-scans. Our study suggests that Al2O3(112̅0) is the most favorable sapphire substrate to realize the envisioned applications of r-BN films.

scholarly journals The impact of point defects in n-type GaN layers on thermal decomposition of InGaN/GaN QWs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mikolaj Grabowski ◽  
Ewa Grzanka ◽  
Szymon Grzanka ◽  
Artur Lachowski ◽  
Julita Smalc-Koziorowska ◽  
...  
Keyword(s):  
Quantum Wells ◽  
High Temperatures ◽  
Point Defects ◽  
X Ray Diffraction ◽  
Helium Ions ◽  
X Ray ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
The Impact ◽  
Ingan Quantum Wells

AbstractThe aim of this paper is to give an experimental evidence that point defects (most probably gallium vacancies) induce decomposition of InGaN quantum wells (QWs) at high temperatures. In the experiment performed, we implanted GaN:Si/sapphire substrates with helium ions in order to introduce a high density of point defects. Then, we grew InGaN QWs on such substrates at temperature of 730 °C, what caused elimination of most (but not all) of the implantation-induced point defects expanding the crystal lattice. The InGaN QWs were almost identical to those grown on unimplanted GaN substrates. In the next step of the experiment, we annealed samples grown on unimplanted and implanted GaN at temperatures of 900 °C, 920 °C and 940 °C for half an hour. The samples were examined using Photoluminescence, X-ray Diffraction and Transmission Electron Microscopy. We found out that the decomposition of InGaN QWs started at lower temperatures for the samples grown on the implanted GaN substrates what provides a strong experimental support that point defects play important role in InGaN decomposition at high temperatures.

Properties of Sputter Deposited ZnO Films Co-doped with Lithium and Phosphorus

2013 ◽  
Vol 1494 ◽  
pp. 77-82
Author(s):  
T. N. Oder ◽  
A. Smith ◽  
M. Freeman ◽  
M. McMaster ◽  
B. Cai ◽  
...  
Keyword(s):  
Rf Magnetron Sputtering ◽  
Zno Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sapphire Substrates ◽  
Hall Effect Measurements ◽  
Sputter Deposited ◽  
P Type ◽  
Post Deposition ◽  
Co Doped

ABSTRACTThin films of ZnO co-doped with lithium and phosphorus were deposited on sapphire substrates by RF magnetron sputtering. The films were sequentially deposited from ultra pure ZnO and Li3PO4 solid targets. Post deposition annealing was carried using a rapid thermal processor in O2 and N2 at temperatures ranging from 500 °C to 1000 °C for 3 min. Analyses performed using low temperature photoluminescence spectroscopy measurements reveal luminescence peaks at 3.359, 3.306, 3.245 eV for the co-doped samples. The x-ray diffraction 2θ-scans for all the films showed a single peak at about 34.4° with full width at half maximum of about 0.17°. Hall Effect measurements revealed conductivities that change from p-type to n-type over time.

AlxGa1-xN-Based Materials and Heterostructures

1996 ◽  
Vol 449 ◽  
Author(s):  
P. Kung ◽  
A. Saxler ◽  
D. Walker ◽  
X. Zhang ◽  
R. Lavado ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Bragg Reflectors ◽  
X Ray Diffraction ◽  
Chemical Vapor Deposition Growth ◽  
X Ray ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
Dimensional Electron Gas ◽  
P Type

ABSTRACTWe present the metalorganic chemical vapor deposition growth, n-type and p-type doping and characterization of AlxGa1-xN alloys on sapphire substrates. We report the fabrication of Bragg reflectors and the demonstration of two dimensional electron gas structures using AlxGa1-xN high quality films. We report the structural characterization of the AlxGa1-xN / GaN multilayer structures and superlattices through X-ray diffraction and transmission electron microscopy. A density of screw and mixed threading dislocations as low as 107 cm-2 was estimated in AlxGa1-xN / GaN structures. The realization of AlxGa1-xN based UV photodetectors with tailored cut-off wavelengths from 365 to 200 nm are presented.

Optical and Structural Properties of AlGaN/GaN Quantum Wells Grown by Molecular Beam Epitaxy

1998 ◽  
Vol 537 ◽  
Author(s):  
Nicolas Grandjean ◽  
Jean Massies ◽  
Mathieu Leroux ◽  
Marguerite Latigt ◽  
Pierre Lefebvre ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Quantum Wells ◽  
Molecular Beam ◽  
Stark Effect ◽  
X Ray Diffraction ◽  
X Ray ◽  
Quantum Confined Stark Effect ◽  
Sapphire Substrates ◽  
Gan Buffer Layer ◽  
Large Quantum

AbstractAIGaN/GaN quantum well (QWs) were grown on (0001) sapphire substrates by molecular beam epitaxy (MBE) using ammonia as nitrogen precursor. The Al composition in the barriers was varied between 8 and 27 % and the well thickness from 4 to 17 monolayers (MLs, 1ML = 2.59Å). X-ray diffraction (XRD) experiments are used to investigate the strain state of both the well and the barriers. The QW transition energy are measured by low temperature photoluminescence (PL). A large quantum confined Stark effect is observed leading to QW luminescence much lower than the emission line of the GaN buffer layer for well width above a certain critical thickness. The built-in electric field responsible for such a phenomenon is deduced from fit of the PL data. Its magnitude is of several hundred kV/cm and increases linearly with the Al composition.

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