Gap state distribution in amorphous hydrogenated silicon carbide films deduced from photothermal deflection spectroscopy

2002 ◽  
Vol 91 (7) ◽  
pp. 4319-4325 ◽  
Author(s):  
K. Chew ◽  
Rusli ◽  
S. F. Yoon ◽  
J. Ahn ◽  
Q. Zhang ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
State Distribution ◽  
Hydrogenated Silicon ◽  
Photothermal Deflection Spectroscopy ◽  
Amorphous Hydrogenated Silicon ◽  
Photothermal Deflection ◽  
Gap State

Microstructure and Dangling Bond Defects in Amorphous Hydrogenated Silicon Deposited Near Room Temperature

1992 ◽  
Vol 258 ◽  
Author(s):  
Man Ken Cheung ◽  
Mark A. Petrich
Keyword(s):  
Room Temperature ◽  
Dangling Bond ◽  
Optimum Conditions ◽  
Band Tail ◽  
Hydrogenated Silicon ◽  
Photothermal Deflection Spectroscopy ◽  
Amorphous Hydrogenated Silicon ◽  
Photothermal Deflection ◽  
Substrate Temperatures ◽  
Absorption Measurements

ABSTRACTThe microstructure of high-density amorphous hydrogenated silicon (a-S.i:H) films deposited at 50°C substrate temperature was revealed by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies to be similar to that of “device-quality” a-Si:H films deposited at standard “optimum” conditions. However, optical absorption measurements of these low microstructure 50°C films with photothermal deflection spectroscopy indicate that they have higher densities of gap state defects and localized band tail states than “device-quality” films deposited at standard substrate temperatures. The correlation between the amount of microstructure and electronic properties is not unique. A low amount of microstructure is a necessary, but not sufficient, requirement for high electronic quality a-Si:H films.

An Investigation of Photo-Induced Degradation by Means of Photothermal Deflection Spectroscopy

1987 ◽  
Vol 95 ◽  
Author(s):  
M. S. Bennett ◽  
S. Wiedeman ◽  
J. L. Newton ◽  
K. Rajan
Keyword(s):  
Optical Absorption ◽  
Fermi Level ◽  
Single Peak ◽  
Defect States ◽  
Hydrogenated Silicon ◽  
Photothermal Deflection Spectroscopy ◽  
Amorphous Hydrogenated Silicon ◽  
Measured Absorption ◽  
Photothermal Deflection

AbstractAbsorption measurements of as deposited and photodegraded intrinsic amorphous hydrogenated silicon films were made using photothermal deflection spectroscopy (PDS). The films were light-soaked in situ using HeNe laser light to simulate AM1 illumination. An increase in subbandgap absorption occurred predominantly near energies of 1.2eV. A simple model was developed in which a density of states function is hypothesized and the resulting optical absorption at subgap energies is calculated. The measured absorption could be well matched in all cases by assuming a single peak of defect states at or slightly below the Fermi level. Further, the observed changes in optical absorption due to degradation could be modeled by increasing the density of the single peak of defect states and moving the Fermi level towards the valence band.

Initial results and long-term clinical follow-up of an amorphous hydrogenated silicon-carbide-coated stent in daily practice

1998 ◽  
Vol 1 (2) ◽  
pp. 81-85
Author(s):  
Clara EE Hanekamp ◽  
Hans JRM Bonnier ◽  
Rolf H Michels ◽  
Kathinka H Peels ◽  
Eric PCM Heijmen ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Daily Practice ◽  
Hydrogenated Silicon ◽  
Amorphous Hydrogenated Silicon ◽  
Initial Results

DEPOSITION-AND-SUBSTRATE TUNABLE PHOTONIC BANDGAP IN OPTICAL RESPONSES OF HYDROGENATED AMORPHOUS SILICON CARBIDE THIN FILMS

2003 ◽  
Vol 17 (09) ◽  
pp. 387-392 ◽  
Author(s):  
NIKIFOR RAKOV ◽  
ARSHAD MAHMOOD ◽  
MUFEI XIAO
Keyword(s):  
Thin Films ◽  
Silicon Carbide ◽  
Photonic Bandgap ◽  
Visible Spectrum ◽  
Incoherent Light ◽  
Hydrogenated Silicon ◽  
Optical Responses ◽  
Amorphous Hydrogenated Silicon ◽  
The Status ◽  
Two Parameters

Amorphous hydrogenated silicon carbide (a-SiC:H) thin films have been prepared by the RF reactive magnetron sputtering technique. The optical properties of the films have been studied by optical spectroscopy with an incoherent light source. The material is commonly regarded as a dielectric. We have discovered however that some films that were prepared under certain deposition conditions and on certain substrates may respond to external light as a metallic thin film, i.e. there are strongly enhanced reflection peaks in the optical spectrum. We have further discovered that some films may have a strong and broadened absorption peak at about 590 nm, which is an apparent photonic bandgap in the visible spectrum. The appearance of the photonic bandgap is very sensitive to two parameters: the substrate and the deposition gas. By changing the two parameters, one shifts the status of the film from with and without the photonic bandgap.

Electronic and Optical Properties of a-Si1−xCx:H Films Produced From Admixtures of Silane and Ditertiarybutylsilane

1994 ◽  
Vol 336 ◽  
Author(s):  
K. Gaughan ◽  
J.M. Viner ◽  
P.C. Taylor
Keyword(s):  
Electrical Conductivity ◽  
Silicon Carbide ◽  
Optical Properties ◽  
Chemical Vapor Deposition ◽  
Amorphous Silicon ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Photothermal Deflection Spectroscopy ◽  
Optical And Electronic Properties ◽  
Photothermal Deflection

ABSTRACTWe investigated the optical and electronic properties of amorphous silicon carbide (a-Si1−xCx:H) films produced by plasma enhanced chemical vapor deposition from admixtures of silane and ditertiarybutylsilane [SiH2 (C4H9) 2 or DTBS] using photothermal deflection spectroscopy, electrical conductivity and its temperature dependence as well as photoconductivity. These a-Si1−xCx:H films exhibit low Urbach energies and high photoconductivities similar to films produced with other carbon feedstock sources. We also present our results for hydrogen diluted a-Si1−xCx:H films using DTBS as the carbon feedstock source.

Growth Mechanism and Chemical Structure of Amorphous Hydrogenated Silicon Carbide (a-SiC:H) Films Formed by Remote Hydrogen Microwave Plasma CVD From a Triethylsilane Precursor: Part 1

2009 ◽  
Vol 15 (1-3) ◽  
pp. 39-46 ◽  
Author(s):  
Aleksander M. Wrobel ◽  
Agnieszka Walkiewicz-Pietrzykowska ◽  
Marja Ahola ◽  
I. Juhani Vayrynen ◽  
Francisco J. Ferrer-Fernandez ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Growth Mechanism ◽  
Chemical Structure ◽  
Microwave Plasma ◽  
Plasma Cvd ◽  
Hydrogenated Silicon ◽  
Amorphous Hydrogenated Silicon ◽  
Microwave Plasma Cvd

Optimization of Optoelectronic Properties of a-SiC:H Films

1993 ◽  
Vol 297 ◽  
Author(s):  
F. Demichelis ◽  
G. Crovini ◽  
C.F. Pirri ◽  
E. Tresso ◽  
R. Galloni ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Silicon Carbide ◽  
Ftir Spectroscopy ◽  
Amorphous Silicon ◽  
Reflectance Spectroscopy ◽  
High Hydrogen ◽  
Hydrogen Dilution ◽  
Photothermal Deflection Spectroscopy ◽  
Device Structures ◽  
Photothermal Deflection

Amorphous silicon carbide films have been deposited by PECVD in SiH4+CH4+H2 mixtures at different hydrogen dilutions. The optoelecuonic properties of the films have been measured by transmittance-reflectance spectroscopy, photothermal deflection spectroscopy and photo and dark electrical conductivity. Structural properties have been obtained by FTIR spectroscopy. It was found that high hydrogen dilution leads to materials of improved quality, p-i-n device structures have been deposited with intrinsic layers at different hydrogen dilution levels.

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