Quasi-Thermodynamic Analysis of Metalorganic Vapor Phase Epitaxy of GaN

1997 ◽  
Vol 468 ◽  
Author(s):  
Shukun Duan ◽  
Dacheng Lu
Keyword(s):  
Phase Diagram ◽  
Phase Diagrams ◽  
Thermodynamic Analysis ◽  
Vapor Phase ◽  
Condensed Phase ◽  
Growth Temperature ◽  
Vapor Interface ◽  
Interface Phase ◽  
Movpe Growth ◽  
Reactor Pressure

ABSTRACTA thermodynamic analysis of GaN grown by MOVPE has been proposed based on quasi-thermodynamic equilibrium established on the solid-vapor interface. Phase diagrams for the MOVPE growth of GaN using TEGa and NH3 has been calculated. The phase diagram is consists of four phases regions: the region for single condensed phase of GaN, the region for double condensed phase of GaN (s) +Ga(l), the etching region with Ga droplets and the etching region without Ga droplets. The effect of growth temperature, reactor pressure, content of carrier gas, deposition ratio of NH3 and V/III ratio upon growth of GaN using MOVPE has been studied.

Thermodynamic analysis of phase diagrams of binary solid solutions of ascending and minimum types: Na2SO4–Ag2SO4, Ag2SO4–K2SO4, Na2SO4–K2SO4

1989 ◽  
Vol 67 (9) ◽  
pp. 1468-1471
Author(s):  
Patrick C. Dawson ◽  
E. A. Secco ◽  
William M. Oxner
Keyword(s):  
Binary System ◽  
Phase Diagrams ◽  
Thermodynamic Analysis ◽  
Solid Solutions ◽  
Condensed Phase ◽  
Solid Phase ◽  
Ionic Melts

The thermodynamic analysis of the condensed phase diagrams of binary system solid solutions of the ascending type, viz. Na2SO4–Ag2SO4 and of the minimum type, ameltrope, viz. Ag2SO4–K2SO4, Na2SO4–K2SO4 is presented. The analysis identifies the basis for ameltrope behavior and provides for the evaluation of α, the fraction of dissociation, and ΔHDiss, the enthalpy of dissociation, of the dissociating component. Keywords: alkali sulfates solid solutions, thermodynamic analysis ameltropes, molten alkali sulfates dissociation, solid–solid phase diagrams, ionic melts.

scholarly journals Phase Diagram of Binary Alloy Nanoparticles under High Pressure

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2929
Author(s):  
Han Gyeol Kim ◽  
Joonho Lee ◽  
Guy Makov
Keyword(s):  
Phase Diagram ◽  
Phase Diagrams ◽  
Interaction Parameter ◽  
Excess Volume ◽  
Eutectic Temperature ◽  
Calphad Method ◽  
Alloy Nanoparticles ◽  
Thermodynamic Conditions ◽  
Nanoparticle System ◽  
Pressure Phase

CALPHAD (CALculation of PHAse Diagram) is a useful tool to construct phase diagrams of various materials under different thermodynamic conditions. Researchers have extended the use of the CALPHAD method to nanophase diagrams and pressure phase diagrams. In this study, the phase diagram of an arbitrary A–B nanoparticle system under pressure was investigated. The effects of the interaction parameter and excess volume were investigated with increasing pressure. The eutectic temperature was found to decrease in most cases, except when the interaction parameter in the liquid was zero and that in the solid was positive, while the excess volume parameter of the liquid was positive. Under these conditions, the eutectic temperature increased with increasing pressure.

Calculation of phase diagrams and thermodynamic properties of 14 additive and reciprocal ternary systems containing Li2CO3, Na2CO3, K2CO3, Li2SO4, Na2SO4, K2SO4, LiOH, NaOH, and KOH

1984 ◽  
Vol 62 (3) ◽  
pp. 457-474 ◽  
Author(s):  
A. D. Pelton ◽  
C. W. Bale ◽  
P. L. Lin
Keyword(s):  
Phase Diagram ◽  
Thermodynamic Properties ◽  
Molten Salt ◽  
Phase Diagrams ◽  
Binary Systems ◽  
Ternary Phase ◽  
Ternary Phase Diagram ◽  
Ternary Systems ◽  
Maximum Error ◽  
Critical Assessment

Phase diagrams and thermodynamic properties of five additive molten salt ternary systems and nine reciprocal molten salt ternary systems containing the ions Li+, Na+, [Formula: see text], OH− are calculated from the thermodynamic properties of their binary subsystems which were obtained previously by a critical assessment of the thermodynamic data and the phase diagrams in these binary systems. Thermodynamic properties of ternary liquid phases are estimated from the binary properties by means of the Conformal Ionic Solution Theory. The ternary phase diagrams are then calculated from these thermodynamic properties by means of computer programs designed for the purpose. It is found that a ternary phase diagram can generally be calculated in this way with a maximum error about twice that of the maximum error in the binary phase diagrams upon which the calculations are based. If, in addition, some reliable ternary phase diagram measurements are available, these can be used to obtain small ternary correction terms. In this way, ternary phase diagram measurements can be smoothed and the isotherms drawn in a thermodynamically correct way. The thermodynamic approach permits experimental data to be critically assessed in the light of thermodynamic principles and accepted solution models. A critical assessment of error limits on all the calculated ternary diagrams is made, and suggestions as to which composition regions merit further experimental study are given.

scholarly journals Vapor-Phase Fabrication and Condensed-Phase Application of a MOF-Node-Supported Iron Thiolate Photocatalyst for Nitrate Conversion to Ammonium

2019 ◽  
Vol 2 (12) ◽  
pp. 8695-8700 ◽  
Author(s):  
Hyeju Choi ◽  
Aaron W. Peters ◽  
Hyunho Noh ◽  
Leighanne C. Gallington ◽  
Ana E. Platero-Prats ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Condensed Phase ◽  
Iron Thiolate ◽  
Supported Iron

The influence of reactor pressure on qualities of GaN layers grown by hydride vapor phase epitaxy

2009 ◽  
Vol 517 (6) ◽  
pp. 2088-2091 ◽  
Author(s):  
X.C. Cao ◽  
D.L. Xu ◽  
H.M. Guo ◽  
C.J. Liu ◽  
Z.J. Yin ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy ◽  
Reactor Pressure

Electronic structure of short-period ZnSe/ZnTe superlattices grown by MOVPE at 300ºC

1993 ◽  
Vol 308 ◽  
Author(s):  
N. Briot ◽  
T. Cloitre ◽  
O. Briot ◽  
P. Boring ◽  
B.E. Ponga ◽  
...  
Keyword(s):  
Growth Temperature ◽  
Lattice Mismatch ◽  
Stokes Shift ◽  
Vapour Phase ◽  
Potential Candidate ◽  
High Quality ◽  
Vapour Phase Epitaxy ◽  
Light Emitting Devices ◽  
Short Period ◽  
Movpe Growth

ABSTRACTThe ZnSe-ZnTe combination is a potential candidate for the realisation of visible light-emitting devices. The lattice mismatch between bulk ZnSe and bulk ZnTe is important (∼ 8%). Therefore, their hetero-structures are strained and high quality superlattices will only be grown if having small periods. This prescription can be fulfilled in the case of metal organic vapour phase epitaxy (MOVPE) growth by combining triethylamine dimethyl zinc adduct with di-isopropyl telluride as precursors for the growth of the ZnTe layers. The growth of high quality ZnTe can then be performed at a temperature of 300ºC , close to the best MOVPE-growth temperature for ZnSe (280ºC). Lowering the growth temperature of ZnTe to this value, we could thus obtain sharp interfaces. This work reports on ZnSe-ZnTe superlattices grown on ZnSe and ZnTe buffers deposited on GaAs substrates. We demonstrate that the stokes-shift between the reflectance and photoluminescence features ( ∼ 40 meV ) measured when the thickness of ZnSe layers does not exceed 20 Å, drastically increases for layer thicknesses beyond this critical value. This, we interpret in terms of the onset of plastic relaxation which favours tellurium diffusion in the ZnSe slices. Then photoluminescence spectra broaden ( contributions of trapped-excitons dominate), and observation of free excitons in reflectance become impossible. We have studied in detail the optical properties of the superlattices and compared our findings with the predictions of a multiband envelope function calculation. We show that both zone centre excitons as well as excitons associated with the miniband dispersions (saddle-point excitons) are observed in these superlattices.

Condensed phase diagram for the In-As-O system

1982 ◽  
Vol 94 (3) ◽  
pp. 205-212 ◽  
Author(s):  
G.P. Schwartz ◽  
W.A. Sunder ◽  
J.E. Griffiths ◽  
G.J. Gualtieri
Keyword(s):  
Phase Diagram ◽  
Condensed Phase

scholarly journals Reactor pressure: growth temperature relation for InN epilayers grown by high-pressure CVD

2010 ◽  
Author(s):  
M. Buegler ◽  
S. Gamage ◽  
R. Atalay ◽  
J. Wang ◽  
I. Senevirathna ◽  
...  
Keyword(s):  
High Pressure ◽  
Growth Temperature ◽  
Temperature Relation ◽  
Reactor Pressure

Effect of growth temperature on Eu-doped GaN layers grown by organometallic vapor phase epitaxy

2010 ◽  
Vol 7 (7-8) ◽  
pp. 2040-2042 ◽  
Author(s):  
Takashi Kawasaki ◽  
Atsushi Nishikawa ◽  
Naoki Furukawa ◽  
Yoshikazu Terai ◽  
Yasufumi Fujiwara
Keyword(s):  
Vapor Phase ◽  
Growth Temperature ◽  
Vapor Phase Epitaxy ◽  
Organometallic Vapor Phase Epitaxy
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