Characterization of Defects in Silicon Ribbons By Combined Ebic and Hvem

1980 ◽  
Vol 2 ◽  
Author(s):  
Horst Strunk ◽  
Brian Cunningham ◽  
Dieter Ast
Keyword(s):  
Electrical Properties ◽  
Grain Boundaries ◽  
Structural Properties ◽  
Minority Carrier ◽  
Higher Order ◽  
Twin Boundaries ◽  
Planar Defects ◽  
Partial Dislocations ◽  
Carrier Recombination

ABSTRACTThe electrical properties and crystallographic nature of linear and planar defects in EFG silicon ribbons were studied. A direct correlation between electrical and structural properties was obtained by imaging the same areas first with EBIC and then with HVEM. Coherent twin boundaries were found to be electrically inactive, but higher order twins and other grain boundaries generally enhanced minority carrier recombination. Partial dislocations confined to coherent twin boundaries were usually electrically active, but in certain instances partial dislocations were observed which had no apparent EBIC contrast.

The formation of hydrogen phases on twin boundaries in Si

1986 ◽  
Vol 44 ◽  
pp. 810-811
Author(s):  
D. M. Vanderwalker
Keyword(s):  
Electrical Properties ◽  
Grain Boundaries ◽  
Point Defects ◽  
Discharge Tube ◽  
Hydrogen Plasma ◽  
High Stress ◽  
Dangling Bonds ◽  
Twin Boundaries ◽  
Pt Electrodes ◽  
Second Phases

When a Si crystal is placed in a hydrogen plasma, H ions diffuse into the crystal and passify dangling bonds at point defects, dislocations, and grain boundaries. The H passivation changes the electrical properties of silicon. The nucleation of H-Si solid second phases was not discussed before this experiment, although H-Si complexes were thought to form. This study is of the formation of H phases on twins in silicon.A Si sample, which was compressed along a <231> axis at 420°C and cooled under a high stress, was placed in a closed gas discharge tube between Pt electrodes. The pressure of the H gas was less than one torr. A hydrogen plasma was produced when 440 volts were applied at 180°C and maintained for 90 minutes.

Characterization of the Structure and Polarity of Twin Boundaries in GaP

1998 ◽  
Vol 510 ◽  
Author(s):  
Dov Cohent ◽  
D.L. Medlin ◽  
C. Barry Carter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Twin Boundary ◽  
Atomic Structure ◽  
Twin Boundaries ◽  
Planar Defects ◽  
Transmission Electron ◽  
Crystallographic Planes

AbstractThe structure of planar defects in GaP films grown by MBE on Si (110) was investigated by transmission electron microscopy. Growth of GaP films on the (110) surface produced numerous microtwins which formed both first and second order twin boundaries. Using high-resolution transmission electron microscopy, the atomic structure of Σ=3 and Σ=9 twin boundaries were studied. Both the Σ=3 and Σ=9 interfaces were observed to facet along specific crystallographic planes. Geometric models of the Σ=9 {221} twin boundary accounting for different polar bonding configurations were proposed and compared with experimental observations.

Characterization of the Absolute Crystal Polarity across Twin Boundaries in Gallium Phosphide Using Convergent-Beam Electron Diffraction

1999 ◽  
Vol 5 (3) ◽  
pp. 173-186 ◽  
Author(s):  
Dov Cohen ◽  
Stuart McKernan ◽  
C. Barry Carter
Keyword(s):  
Electron Diffraction ◽  
Gallium Phosphide ◽  
Convergent Beam Electron Diffraction ◽  
Twin Boundaries ◽  
Planar Defects ◽  
Beam Electron ◽  
Polar Orientation ◽  
Individual Grains ◽  
Convergent Beam

The measurement of absolute crystal polarity is crucial to understanding the structural properties of many planar defects in compound semiconductors. Grain boundaries, including twin boundaries, in the sphalerite lattice are uniquely characterized by the crystallographic misorientation of individual grains and the direction of the crystal polarity in domains adjoining the grain boundary. To evaluate crystal polarity in gallium phosphide (GaP), asymmetrical interference contrast in convergent-beam electron-diffraction (CBED) patterns was used to ascertain the nature and direction of polar bonds. The direction of the asymmetry in the electron diffraction reflections was correlated with the crystal polarity of a sample with known polarity. The CBED technique was applied to determine the polar orientation of grains adjoining Σ = 3 coherent and lateral twin boundaries in polycrystalline GaP.

Characterization of 4H-SiC Epitaxial Layers by Microwave Photoconductivity Decay

2005 ◽  
Vol 483-485 ◽  
pp. 405-408 ◽  
Author(s):  
R.J. Kumar ◽  
Peter A. Losee ◽  
Can Hua Li ◽  
Joseph Seiler ◽  
I. Bhat ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Decay Rate ◽  
Minority Carrier ◽  
Epitaxial Layers ◽  
Pin Diodes ◽  
Recombination Lifetime ◽  
Carrier Recombination ◽  
Decay Times ◽  
Photoconductivity Decay

A Microwave Photoconductivity Decay (M-PCD) technique which senses changes insample conductivity as carriers recombine following excitation by a laser pulse, has been used to determine the minority carrier recombination lifetime from the decay rate of carriers in 4H-SiC epitaxial layers. Decay times varying from 60 ns to 500 ns have been measured, with the decay increasing with thickness. Device simulations show that I-V characteristics of pin diodes fabricated with these epitaxial layers are compatible with the observed decay times.

An Enhanced Photoresponse at Dislocation Subgrain Boundaries Revealed by X-Ray Topography of Polysilicon Solar Cells

1981 ◽  
Vol 5 ◽  
Author(s):  
S.M. Johnson ◽  
R.W. Armstrong ◽  
R.G. Rosemeier ◽  
G.M. Storti ◽  
H.C. Lin ◽  
...  
Keyword(s):  
Solar Cells ◽  
Dislocation Density ◽  
Grain Boundaries ◽  
Minority Carrier ◽  
Diffusion Length ◽  
Junction Depth ◽  
Twin Boundaries ◽  
Pure Material ◽  
Minority Carrier Diffusion Length ◽  
X Ray

ABSTRACTAn enhanced photoresponse at dislocation subgrain boundaries (in comparison with grain boundaries and dislocation-associated twin boundaries) is attributed to an increased junction depth at their positions relative to the value of the minority carrier diffusion length, Ln. For reasonably pure material, Ln is determined by the dislocation density. The dislocation microstructure of polysilicon solar cells is advantageously studied by means of the several x-ray topography techniques.

Synthesis and Characterization of Low Density Bi-2223 Superconductors via Co-Precipitation Method

2015 ◽  
Vol 1107 ◽  
pp. 611-615 ◽  
Author(s):  
I.N. Syuhaida ◽  
H. Azhan ◽  
K. Azman ◽  
C.M.N. Azura ◽  
M. Robaiah
Keyword(s):  
Electrical Properties ◽  
Structural Properties ◽  
Precipitation Method ◽  
Crystallographic Structure ◽  
Low Density ◽  
X Ray Diffraction ◽  
Tetragonal Form ◽  
Optimum Porosity ◽  
Co Precipitation

High temperature Bi1.6Pb0.4Sr2Ca2Cu3Oδ of low density has been synthesized via co-precipitation method and its electrical and structural properties have been studied. The optimum porosity of the samples was obtained using variety amount of sucrose C12H22O11 which is used as supplementary filler. The electrical properties of superconductor such as critical temperature, Tc and critical current density, Jc were determined using the four-probe method. X-ray diffraction (XRD) was used to analyze the structural properties of the samples. The density of samples was measured using densitometer. The obtained results have revealed a significant influence of the pore presence in superconducting samples on the electrical properties. The Tc for low density Bi-2223 with 0.1g sugar sucrose is much higher compared to 0.05g, 0.15g and standard sample which is Tc zero is 98 K. The Jc for low density Bi-2223 with 0.1g sugar sucrose is 6 A/cm2 at 60 K which is higher than high density samples. The crystallographic structure remains in the tetragonal form where a=b≠c for all samples.

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