Electronic and Optical Properties of A—(Si, Ge):H Alloys

1985 ◽  
Vol 49 ◽  
Author(s):  
Vikram Daial ◽  
James F. Booker ◽  
Mark Leonard
Keyword(s):  
Optical Properties ◽  
High Temperature ◽  
Glow Discharge ◽  
Gas Phase ◽  
Valence Band ◽  
Growth Temperature ◽  
Low Temperatures ◽  
Electronic And Optical Properties ◽  
Photo Conductivity ◽  
Amorphous Si

AbstractWe describe the preparation and electronic and optical properties of amorphous (Si, Ge) alloys. A—(Si, Ge):H alloys were prepared by glow discharge decomposition of SiH4 and GeH4. The bandgap was varied between 1.78 and 1.42 eV by changing the GeH4:SiH4 ratio in the gas phase. We find a distinct influence of growth temperature on electronic properties. Films grown at low temperatures (200–250C) tendto have much lower photo conductivity than films grown at higher temperatures (300–325C). The electron (μ τ) products of high temperature films are general> 1X10–7 cm2/V. We also obtain very sharp valence band tails in a—(Si, Ge):H alloys, with slopes of ∼ 40 meV. The hole (μ τ) product is generally ∼1–2X10–8 cm2/V. All these properties suffer a catastrophic decline when bandgap is reduced below about 1.5 eV.

The Influence of Growth Temperature on Oxygen Concentration in GaN Buffer Layer

2008 ◽  
Vol 1068 ◽  
Author(s):  
Ewa Dumiszewska ◽  
Wlodek Strupinski ◽  
Piotr Caban ◽  
Marek Wesolowski ◽  
Dariusz Lenkiewicz ◽  
...  
Keyword(s):  
High Temperature ◽  
Buffer Layer ◽  
Oxygen Concentration ◽  
Growth Temperature ◽  
Low Temperatures ◽  
Buffer Layers ◽  
Crystalline Quality ◽  
Temperature Growth ◽  
Gan Buffer Layer

ABSTRACTThe influence of growth temperature on oxygen incorporation into GaN epitaxial layers was studied. GaN layers deposited at low temperatures were characterized by much higher oxygen concentration than those deposited at high temperature typically used for epitaxial growth. GaN buffer layers (HT GaN) about 1 μm thick were deposited on GaN nucleation layers (NL) with various thicknesses. The influence of NL thickness on crystalline quality and oxygen concentration of HT GaN layers were studied using RBS and SIMS. With increasing thickness of NL the crystalline quality of GaN buffer layers deteriorates and the oxygen concentration increases. It was observed that oxygen atoms incorporated at low temperature in NL diffuse into GaN buffer layer during high temperature growth as a consequence GaN NL is the source for unintentional oxygen doping.

Investigation of 3C-SiC(111) Homoepitaxial Growth by CVD at High Temperature

2010 ◽  
Vol 645-648 ◽  
pp. 127-130 ◽  
Author(s):  
Nikoletta Jegenyes ◽  
Jean Lorenzzi ◽  
Véronique Soulière ◽  
Jacques Dazord ◽  
François Cauwet ◽  
...  
Keyword(s):  
High Temperature ◽  
Surface Morphology ◽  
Gas Phase ◽  
Chemical Vapour Deposition ◽  
Growth Temperature ◽  
Vapour Deposition ◽  
Defect Density ◽  
Chemical Vapour ◽  
Defect Size ◽  
Homoepitaxial Growth

Starting from 3C-SiC(111) layers grown by Vapour-Liquid-Solid mechanism, homoepitaxial growth by Chemical Vapour Deposition was carried out on top of these seeds. The effect of the growth temperature and of the C/Si ratio in the gas phase was investigated on the surface morphology, the roughness and the defect density. It was found that the initial highly step-bunched surface of the VLS seeds could be greatly smoothen using appropriate conditions. These conditions were also found to reduce significantly the defect size and/or density at the surface.

Electronic and optical properties of glow-discharge amorphous silicon-carbon alloys

1984 ◽  
Vol 49 (5) ◽  
pp. 489-501 ◽  
Author(s):  
J. Bullot ◽  
M. Gauthier ◽  
M. Schmidt ◽  
Y. Catherine ◽  
A. Zamouche
Keyword(s):  
Optical Properties ◽  
Glow Discharge ◽  
Amorphous Silicon ◽  
Electronic And Optical Properties ◽  
Silicon Carbon

The Role of Gas Phase Decomposition in the ALE Growth of III–V Compounds

1991 ◽  
Vol 222 ◽  
Author(s):  
K. G. Reid ◽  
H. M. Urdianyk ◽  
N. A. El-Masry ◽  
S. M. Bedair
Keyword(s):  
Boundary Layer ◽  
High Temperature ◽  
Gas Phase ◽  
Exposure Time ◽  
Growth Temperature ◽  
Phase Decomposition ◽  
Temperature Growth ◽  
Mocvd Reactor ◽  
Maximum Exposure

ABSTRACTThe effects of the growth temperature and exposure time to TMGa for ALE of gallium arsenide was studied using TMGa and AsH3 in a modified, vertical, atmospheric, MOCVD reactor with a rotating susceptor. It was found that the temperature range for ALE growth could -be extended from 450°C to 700°C by adjustment of the exposure time to TMGa. The maximum exposure time to TMGa was found to decrease as growth temperature increased with high temperature growth limited to exposures of only fractions of a second. Beyond a critical exposure time to TMGa, gallium droplets form on the surface. It is known that premature decomposition of TMGa in the heated gaseous boundary layer causes the formation of the gallium droplets and the consequent loss of ALE growth.

Electronic Transport and the Density of States Distribution in a-(Si, Ge):H, F Alloys

1986 ◽  
Vol 70 ◽  
Author(s):  
S. Aljishi ◽  
Z E. Smith ◽  
D. Slobodin ◽  
J. Kolodzey ◽  
V. Chu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Glow Discharge ◽  
Amorphous Silicon ◽  
Density Of States ◽  
Electronic Transport ◽  
Silicon Germanium ◽  
Drift Mobility ◽  
Electronic And Optical Properties ◽  
Reported Data ◽  
Amorphous Silicon Germanium

ABSTRACTThe electronic and optical properties of amorphous silicon-germanium alloys produced by d.c. and r.f. glow discharge are reported. Data on the sub-gap absorption, dark and photo conductivities, drift mobilities and drift mobility-lifetime products are used to propose a density of states model.

ChemInform Abstract: Gas Phase to Solid State Evolution of the Electronic and Optical Properties of Conjugated Chains: A Theoretical Investigation

ChemInform ◽  
2001 ◽  
Vol 32 (15) ◽  
pp. no-no
Author(s):  
Jerome Cornil ◽  
Donizetti A. Dos Santos ◽  
David Beljonne ◽  
Zhigang Shuai ◽  
Jean-Luc Bredas
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
Gas Phase ◽  
Theoretical Investigation ◽  
Electronic And Optical Properties ◽  
State Evolution

Properties of A—Sin:H Films Prepared by Glow Discharge of Si2H6—Nh3 Gas Mixture

1985 ◽  
Vol 49 ◽  
Author(s):  
Y. Kojima ◽  
S. Narikawa ◽  
T. Matsuyama ◽  
E. Imada ◽  
H. Nojima ◽  
...  
Keyword(s):  
Optical Properties ◽  
Glow Discharge ◽  
Deposition Rate ◽  
Molar Ratio ◽  
Gas Mixture ◽  
High Deposition Rate ◽  
Electrical And Optical Properties ◽  
Optical Gap ◽  
Wide Range ◽  
Photo Conductivity

AbstractThe electrical and optical properties of a—SiNx:H films prepared by the glow discharge of Si2H6-NH3 gas mixture have been investigated in a wide range of the molar ratio of NH3 to Si2H6 The maxima of the dark—and the photo—conductivity are observed at the molar ratio of about 10-1. At this molar ratio the deposition rate is about33 Å/sec. The optical gap and the compositional ratio of nitrogen to silicon change smoothly from those of a—Si:H to those of a—Si3N4. It is found that the valency control is possible in a—SiNx:H films prepared at a high deposition rate.

Temperature Dependence of the Photoconductivity and the Near Absence of Light-Induced Defects in a-SixGe1-x:H

1996 ◽  
Vol 420 ◽  
Author(s):  
H. Fritzsche ◽  
P. Stradins ◽  
G. Belomoin
Keyword(s):  
Glow Discharge ◽  
Temperature Dependence ◽  
Conduction Band ◽  
Low Temperatures ◽  
Elevated Temperatures ◽  
Thermal Quenching ◽  
Amorphous Si ◽  
Induced Defects ◽  
Band Tails

AbstractThe photoconductivities ap of glow discharge deposited a-Ge:H and amorphous Si-Ge alloys prepared in different laboratories were measured between 4.2K and 300K and compared with σp(T) of intrinsic and compensated a-Si:H films. The alloys as well as a-Ge:H do not exhibit thermal quenching of σp(T) at elevated temperatures which suggests that the valence and conduction band tails have similar widths. Remarkable is the near absence of light-induced metastable defects in the alloys as well as in a-Ge:H even after prolonged exposures at low temperatures.

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