The Effect of Phosphine Pressure on the Band Gap of Ga0.5In0.5P

1994 ◽  
Vol 340 ◽  
Author(s):  
Sarah R. Kurtz ◽  
D. J. Arent ◽  
K. A. Bertness ◽  
J. M. Olson
Keyword(s):  
Growth Rate ◽  
Surface Structure ◽  
Band Gap ◽  
Surface Diffusion ◽  
Parameter Space ◽  
Growth Temperature ◽  
Growth Rates ◽  
Diffusion Length ◽  
Group V ◽  
Group Iii

ABSTRACTThe band gap of Ga0.51n0.5P is studied as a function of phosphine pressure, B-type substrate misorientation, growth rate, and growth temperature, with emphasis placed on the effect of the phosphine pressure. Over most of the parameter space explored (high temperatures, large substrate misorientations, and low growth rates), the band gap increases with decreasing phosphine. This increase is proposed to be caused by lower phosphorus coverage of the surface, resulting in a different surface structure that doesn't promote ordering. The implications of this effect on the observed variations of band gap with growth temperature, substrate misorientation, and growth rate are discussed. For regions of parameter space in which the ordering appears to be kinetically limited by surface diffusion, the band gap increases slightly with phosphine pressure, consistent with observations that increased group-V pressure decreases the group-III surface diffusion length.

MOVPE GaN Gas-Phase Chemistry for Reactor Design and Optimization

1996 ◽  
Vol 449 ◽  
Author(s):  
S. A. Safvi ◽  
J. M. Redwing ◽  
A. Thon ◽  
J. S. Flynn ◽  
M. A. Tischler ◽  
...  
Keyword(s):  
Growth Rate ◽  
Gas Phase ◽  
Growth Rates ◽  
Operating Conditions ◽  
Gas Phase Reactions ◽  
Group V ◽  
Group Iii ◽  
Design And Optimization ◽  
Gas Phase Chemistry ◽  
Phase Chemistry

ABSTRACTThe results of gas phase decomposition studies are used to construct a chemistry model which is compared to data obtained from an experimental MOVPE reactor. A flow tube reactor is used to study gas phase reactions between trimethylgallium (TMG) and ammonia at high temperatures, characteristic to the metalorganic vapor phase epitaxy (MOVPE) of GaN. Experiments were performed to determine the effect of the mixing of the Group III precursors and Group V precursors on the growth rate, growth uniformity and film properties. Growth rates are predicted for simple reaction mechanisms and compared to those obtained experimentally. Quantification of the loss of reacting species due to oligmerization is made based on experimentally observed growth rates. The model is used to obtain trends in growth rate and uniformity with the purpose of moving towards better operating conditions.

The Effect of Substrate Orientation on the Properties of (Ga, Al)As Grown by Gas Source Molecular Beam Epitaxy

1988 ◽  
Vol 144 ◽  
Author(s):  
A. Sandhu ◽  
T. FUJII ◽  
H. Ando ◽  
H. Ishikawa ◽  
E. Miyauchi
Keyword(s):  
Growth Rate ◽  
Growth Conditions ◽  
Group V ◽  
Group Iii ◽  
Al Content ◽  
Gas Source ◽  
Compensation Ratio ◽  
Potential Applications ◽  
Si Doped ◽  
Gas Source Mbe

ABSTRACTWe have carried out the first systemmatic investigation on the effect of substrate temperature and arsenic partial pressure on the morphology, growth rate, and compensation ratio of Si-doped GaAs, and the Al content of AlxGa1−xAs grown on just-cut (100), (110), (111)A&B, (311)A&B orientated GaAs substrates by gas source MBE (GSMBE). Triethylgallium ( TEG, Ga(C2H5)3 ) and triethylaluminium ( TEA, Al(C2H5)3 ) were used as group III sources, and solid arsenic ( As4 ) and silicon as a group V and IV sources, respectively. The best GaAs mophology was obtained at relatively high temperatures and arsenic pressures. The A orientations were identified as ‘fast surfaces,’ with the GaAs growth rate being comparable to the (100) orientation. The B orientations were identified as ‘slow surfaces,’ with the GaAs growth rate being much less (approximately 50% for the (111)B orientation ) than on the (100) orientation. The least compensated Si-doped GaAs was grown on the (311)A orientated substrate. The Al content, x, (nominally x=0.27 for (100)) of AlxGas1−xAs grown on (110), (111)A&B, was less than 0.05 and not affected by the growth conditions. The Al content of epilayers grown on (311)A&B ranged between x=0.1 to 0.27, strongly depending on the growth temperature.These results show that using GSMBE we can selectively modifying a large range of (Ga,Al)As crystal properties. Potential applications include the selective growth and realisation of ultra-fine and planar structures and devices.

Optimal growth temperature hypothesis: Why do anchovy flourish and sardine collapse or vice versa under the same ocean regime?

2007 ◽  
Vol 64 (5) ◽  
pp. 768-776 ◽  
Author(s):  
Akinori Takasuka ◽  
Yoshioki Oozeki ◽  
Ichiro Aoki
Keyword(s):  
Growth Rate ◽  
Growth Temperature ◽  
Growth Rates ◽  
Synergistic Effects ◽  
Larval Growth ◽  
Optimal Growth ◽  
Regime Shifts ◽  
Optimal Growth Temperature ◽  
Sea Temperature ◽  
Japanese Sardine

The out-of-phase population oscillations between anchovy and sardine have been attributed to climate changes. However, the biological processes causing these species alternations have remained unresolved. Here we propose a simple "optimal growth temperature" hypothesis, in which anchovy and sardine regime shifts are caused by differential optimal temperatures for growth rates during the early life stages. Dome-shaped relationships between growth rate and sea temperature were detected for both Japanese anchovy (Engraulis japonicus) and Japanese sardine (Sardinops melanostictus) larvae based on otolith microstructure analysis. The optimal growth rate for anchovy larvae occurred at 22.0 °C, whereas that for sardine larvae occurred at 16.2 °C. Ambient temperatures have historically fluctuated between these optima, which could lead to contrasting fluctuations in larval growth rates between the two species. This simple mechanism could potentially cause the shifts between the warm anchovy regime and the cool sardine regime in the western North Pacific. Although retrospective analysis suggested synergistic effects of other factors (e.g., trophic interactions and fishing), the optimal growth temperature concept would provide a possible biological mechanism of anchovy and sardine regime shifts.

Competing Kinetic and Thermodynamic Processes in the Growth and Ordering of Ga0.5In0.5P

1993 ◽  
Vol 312 ◽  
Author(s):  
Sarah R. Kurtz ◽  
J. M. Olson ◽  
D. J. Arent ◽  
A. E. Kibbler ◽  
K. A. Bertness
Keyword(s):  
Growth Rate ◽  
High Temperature ◽  
Band Gap ◽  
Growth Temperature ◽  
Growth Parameter ◽  
High Growth ◽  
High Growth Rate ◽  
Temperature Growth ◽  
Rate Region ◽  
Thermodynamic Processes

AbstractThe band gap of Ga0.5In0.5P is studied as a function of growth temperature, growth rate, and substrate misorientation. As each of these parameters is independently varied the band gap first decreases, then increases, resulting in “U” shaped curves. Each “U” shaped curve shifts if any other growth parameter is varied. The data presented here can be divided into two regions of parameter space. In the low temperature, low substrate misorientation, high growth rate region, the band gap is shown to decrease with increasing growth temperature, decreasing growth rate, and increasing substrate misorientation. In the high temperature, high substrate misorientation, low growth rate region, the opposite trends are observed. The implications of these data on the ordering mechanism are discussed.

Mombe Growth of GaP and its Efficient Photoeniiancement at Low Temperatures

1992 ◽  
Vol 242 ◽  
Author(s):  
Masahiro Yoshimoto ◽  
Tsuzumi Tsuji ◽  
Atsushi Kajimoto ◽  
Hiroyuki Matsunami
Keyword(s):  
Growth Rate ◽  
Laser Irradiation ◽  
Growth Rates ◽  
Low Temperatures ◽  
Epitaxial Layers ◽  
Smooth Surfaces ◽  
Group Iii ◽  
Substrate Temperatures

ABSTRACTGaP epllayers grown at temperatures ranging from 420 to 500°C had smooth surfaces and streaky RHEED patterns. The decomposition of group-III sources of TEGa limits the growth rates of GaP at lower substrate temperatures(<390 °C ). The growth rate of GaP epitaxial layers was efficiently enhanced by N2∼laser irradiation at lower substrate temperatures.

Surface diffusion length during MBE and MOMBE measured from distribution of growth rates

1991 ◽  
Vol 115 (1-4) ◽  
pp. 423-427 ◽  
Author(s):  
T. Isu ◽  
M. Hata ◽  
Y. Morishita ◽  
Y. Nomura ◽  
Y. Katayama
Keyword(s):  
Surface Diffusion ◽  
Growth Rates ◽  
Diffusion Length

Mombe Growth of GaP and its Efficient Photoeniiancement at Low Temperatures

1992 ◽  
Vol 242 ◽  
Author(s):  
Masahiro Yoshimoto ◽  
Tsuzumi Tsuji ◽  
Atsushi Kajimoto ◽  
Hiroyuki Matsunami
Keyword(s):  
Growth Rate ◽  
Laser Irradiation ◽  
Growth Rates ◽  
Low Temperatures ◽  
Epitaxial Layers ◽  
Smooth Surfaces ◽  
Group Iii ◽  
Substrate Temperatures

ABSTRACTGaP epllayers grown at temperatures ranging from 420 to 500°C had smooth surfaces and streaky RHEED patterns. The decomposition of group-III sources of TEGa limits the growth rates of GaP at lower substrate temperatures(<390 °C ). The growth rate of GaP epitaxial layers was efficiently enhanced by N2∼laser irradiation at lower substrate temperatures.

The Farthest Reaches of a-Si,Ge:H,F Parameter Space… Where no One Has Gone Before

1992 ◽  
Vol 258 ◽  
Author(s):  
P.A. Morin ◽  
N.W. Wang ◽  
S. Wagner
Keyword(s):  
Growth Rate ◽  
Parameter Space ◽  
Growth Rates ◽  
Film Growth ◽  
Defect Density ◽  
Initial Defect ◽  
Figures Of Merit ◽  
Rate Dependent ◽  
Deposition Parameters ◽  
Defect Densities

ABSTRACTWe report the deposition parameters for optimized a-Si,Ge:H,F alloys in the range of optical (Taue) gap of 1.22eV to 1.65eV. These deposition parameters were optimized using the photosensitivity and initial defect density as figures of merit. We observe two distinct regimes of film growth rate, dependent on the choice of source gases. Growth from fluoride source gases results in a growth rate of less than 0.6 Ås--1. Growth from a mixture of fluorides and silane gives a range of growth rates from 2 Ås-l to 5.5Ås1. Alloys in both regimes display the low defect densities and the high photosensitivities required for devices.

scholarly journals Лимитирующие режимы роста III-V нитевидных нанокристаллов

2020 ◽  
Vol 46 (17) ◽  
pp. 26
Author(s):  
В.Г. Дубровский ◽  
А.С. Соколовский ◽  
H. Hijazi
Keyword(s):  
Growth Rate ◽  
Generalized Equation ◽  
Nanowire Growth ◽  
Vapor Liquid Solid ◽  
Group V ◽  
Growth Environment ◽  
Group Iii ◽  
Deposition Surface ◽  
Vapor Liquid Solid Growth ◽  
Vapor Liquid

Theoretical analysis is presented for vapor-liquid-solid growth of III-V nanowires in the presence of three competing processes of the group V deposition, surface diffusion of group III adatoms and nucleation of islands at the liquid-solid interface. A generalized equation for the nanowire growth rate is obtained which can be limited of one of the three processes depending on the growth environment. Different regimes of vapor-liquid-solid growth of III-V nanowires are analyzed depending on the group III and V influxes and nanowire radius.

Selection for biomass production based on respiration parameters in eucalypts: acclimation of growth and respiration to changing growth temperature

1996 ◽  
Vol 26 (9) ◽  
pp. 1569-1576 ◽  
Author(s):  
R.S. Criddle ◽  
T.S. Anekonda ◽  
R.M. Sachs ◽  
R.W. Breidenbach ◽  
L.D. Hansen
Keyword(s):  
Growth Rate ◽  
Biomass Production ◽  
Growth Temperature ◽  
Growth Rates ◽  
Heat Rate ◽  
Metabolic Rates ◽  
Different Temperatures ◽  
Controlled Environments ◽  
Respiration Parameters

This paper examines the relation between respiratory physiology and growth rate and the effects of environment on this relation for the purpose of developing means for accelerating and improving selection of trees for biomass production. The relations among biomass production, respiratory metabolism, and growth temperature in controlled environments were determined for three Eucalyptus genotypes (clones). Eucalyptuscamaldulensis 4016, E. camaldulensis C11, and Eucalyptusgundal (Eucalyptusgunnii × Eucalyptusdalrympleana hybrid) GD1 were selected for this study because of known qualitative differences in their field growth responses to temperature. These clones were grown in controlled environments at three temperatures. Measurements were made of growth rate, metabolic heat rate, and dark CO2 production rate for plants grown at each of the three temperatures. This allowed determination of respiration rates of plants originally adapted for growth in different climates, but acclimated during growth at three different controlled temperatures, and also determination of respiration changes resulting from short-term changes in temperature. Growth rates of the three clones differed in their patterns of response to changes in growth temperature. For example, C11 grew most rapidly at the highest temperature, while GD1 was slowest at high temperature. Metabolic rates and the temperature dependence of metabolic rates of the clones differed and the pattern of differences changed when plants became acclimated to growth at different temperatures. Changes in metabolic properties of the three clones with growth and measurement temperatures are consistent with the growth rate changes. In general, increased growth rate was accompanied by increased respiration rate measured either as heat rate or as rate of CO2 production. Growth rates were inversely related to two measures of metabolic energy use efficiency. Growth rates decreased as values of heat loss per gram dry weight produced and values of heat loss per mole of CO2 produced increased. Recognition of these relations between growth rate and respiration parameters at different temperatures in controlled environement may allow prediction of relative growth rate performance of Eucalyptus clones over a range of growth climates.

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