ChemInform Abstract: MAXIMUM POWER SPECTROSCOPY OF N-TYPE AMORPHOUS HYDROGENATED SILICON, CRYSTALLINE SILICON, CADMIUM SELENIDE, AND INDIUM PHOSPHIDE IN NONAQUEOUS PHOTOELECTROCHEMICAL CELLS

1985 ◽  
Vol 16 (22) ◽  
Author(s):  
J. M. ROSAMILIA ◽  
B. MILLER
Keyword(s):  
Indium Phosphide ◽  
Cadmium Selenide ◽  
Crystalline Silicon ◽  
Maximum Power ◽  
Photoelectrochemical Cells ◽  
Hydrogenated Silicon ◽  
Amorphous Hydrogenated Silicon

scholarly journals Time-resolved reflectivity technique: improvement and applications

1999 ◽  
Vol 1 (2) ◽  
pp. 101-105 ◽  
Author(s):  
K. M. A. EL-Kader
Keyword(s):  
Energy Density ◽  
Laser Irradiation ◽  
Crystalline Silicon ◽  
Threshold Energy ◽  
Time Resolved ◽  
Hydrogenated Silicon ◽  
Maximum Reflectivity ◽  
Amorphous Hydrogenated Silicon ◽  
Melting Threshold ◽  
Constant Energy Density

A new method for determination of the reflectivity of Si in different phase transitions during pulsed laser irradiation is presented in this paper. This method is applied on TRR spectra of crystalline silicon (c-Si) in a medium of oxygen and amorphous hydrogenated silicon (a-Si: H). Time resolved reflectivity (TRR) measurements on silicon has been made during pulsed XeCl excimer laser irradiation (308 nm, 28nm FWHM) in a medium of oxygen. The samples were irradiated in the energy density range400−100mJ/cm2. The reflectivity was measured with a probe He-Ne laser (632.8 nm). Depending on the energy density of the excimer pulse, heating, melting and resolidification of the surface were monitored by TRR spectra. From these measurements we were able to determine the melting threshold energy density for c-Si, depending on the energy densities, time of melting and maximum reflectivity have been measured. TRR spectra of a sample with3μm thick a-Si layer for first shot of measurements were calibrated. A series of a-Si: H samples of the same thickness (0.34μm) irradiated with a constant energy density450mJ/cm2and the three consecutive TRR spectra of the irradiated samples were calibrated.

Diffusion of Hydrogen and Deuterium in Stack Systems of SixNyHz/SixNyDz and Crystalline Si

2000 ◽  
Vol 609 ◽  
Author(s):  
Christoph Boehme ◽  
Gerald Lucovsky
Keyword(s):  
Silicon Nitride ◽  
Crystalline Silicon ◽  
Chemical Vapor ◽  
Ex Situ ◽  
Rapid Thermal Anneal ◽  
Hydrogenated Silicon ◽  
Bond Density ◽  
Amorphous Hydrogenated Silicon ◽  
Dominant Process ◽  
Diffusion Of Hydrogen

ABSTRACTH/D-, N-H/D- and Si-H/D-bond density changes were investigated in stacks consisting of a Cz-Si substrate, a thin layer of SiO2, amorphous deuterated silicon nitride as well as amorphous hydrogenated silicon nitride in order to see if the post deposition anneal of a-SixNyHz layers on crystalline silicon wafers can actually lead to a migration of H atoms into the Si-bulk, which is an important question in regard to emitter passivation of Si-solar cells.The stacks were grown with remote plasma enhanced chemical vapor deposition (RPECVD). A low temperature (≈200°C) process of down stream injected ammonia (NH3) and silane (SiH4) activated by an upstream injected He-plasma, produced through RF-radiation (13.65MHz) was used. Thermal treatment was executed by ex situ rapid thermal anneal in Ar ambient. For the measurements of H and D bond densities, FTIR was employed while SIMS determined atomic densities of H, D and O in the c-Si/nitride interface region. The experiments showed that H transport in silicon nitride is determined by several mechanisms including diffusion and dissociation processes and that silicon nitride deposited with high ammonia to silane ratios can produce molecular species like ammonia and H2. The study of the reaction dynamics showed that the production of molecular hydrogen is the most dominant process as long as Si-H-bonds are present in the system. After their exhaustion, an ammonia producing reaction prevails that leads with increasing temperatures to lower densities in the nitride films.

Nuclear Magnetic Resonance (NMR) of Porous Silicon

1996 ◽  
Vol 452 ◽  
Author(s):  
W. K. Chang ◽  
M. Y. Liao ◽  
K. K. Gleason
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Porous Silicon ◽  
Crystalline Silicon ◽  
Bulk Single Crystal ◽  
Hydrogenated Silicon ◽  
Low Temperature Annealing ◽  
Amorphous Hydrogenated Silicon ◽  
Silicon Nanocrystallites ◽  
Nuclear Magnetic

AbstractPorous silicon (PS) was characterized by 1H, 19F and 29Si solid-state nuclear magnetic resonance (NMR). On freshly prepared samples, hydrogen contents were between 3 × 1014 and 3 × 1015 per cm2 of PS surface area, while fluorine concentrations were below the detection limit. Cross-polarization (CP) was used to selectively observe the 29Si near the hydrogen passivation. The features of the 29Si NMR spectra are assigned as (O)2(Si)Si-H (-50 ppm), (O)3Si-H (-84 ppm), (Si)3Si-H (-91 ppm), (Si)2Si-H2 (-102 ppm) and (O)4Si (-109 ppm). Changes resulting from low temperature annealing in air and an HF soak were observed by both NMR and infrared spectroscopy. The 29Si NMR line widths for PS fall between those for crystalline silicon and those for amorphous hydrogenated silicon films (a-Si:H), suggesting disorder near the PS surface is intermediate between these extremes. However, comparison of the isotropie chemical shift values shows that the bonding in the disordered regions of PS differs from that found in a-Si:H. In addition, the sharp 29Si NMR resonance observed in the bulk single crystal starting material can not be resolved in the spectra of PS. Thus, well-ordered silicon nanocrystallites in the PS are either several bond-lengths removed from hydrogen or comprise only a small fraction of the PS layer.

Pulsed ruby laser accelerated degradation of amorphous hydrogenated silicon

1993 ◽  
Vol 164-166 ◽  
pp. 235-238 ◽  
Author(s):  
O. Klíma ◽  
O. Štika ◽  
Ho Tha Ha ◽  
S. Fouad Abdel Hamied ◽  
J. Stuchlík ◽  
...  
Keyword(s):  
Ruby Laser ◽  
Hydrogenated Silicon ◽  
Accelerated Degradation ◽  
Amorphous Hydrogenated Silicon

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
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