30 Result(s)
within
F. Demichelis
Inorganic Chemistry
-
Article
Structural and Electrical Properties of Undoped Microcrystalline Silicon Grown by 70 MHz and 13.56 MHz PECVD
Microcrystalline silicon films deposited by plasma methods have an optical absorption for photon energies above 2.0 eV lower than a-Si:H films and can be efficiently doped with boron or phosphorus. The most wi...
-
Article
Effect of Carbon Content on the Optical Properties of a-CSiSn:H Alloy
A careful study of the optical constants of a-CSiSn:H films prepared under very similar conditions with varying C or Sn concentration is here presented. Results of an attempt via the use of an effective medium...
-
Article
Brightness Degradation Controlled by Current Induced Metastable Defect Creation in a-SiC:H Based Light Emitting Diodes
A study of the electroluminescence degradation of a-SiC:H based light emitting devices (LED) is presented for the first time. The best initial peak brightness obtained is 4.2 cd/m2. All LEDs reported in this pape...
-
Article
Thermal Modulated Esr For The Study Of Defects In a-SiC:H Films
In this work we present Thermal Modulation Electron Spin Resonance Measurements performed on a-SiC:H films prepared by Plasma Enhanced Chemical Vapour Deposition with energy gap in the range 1.8–2.5 eV. The re...
-
Article
Boron and Phosphorus Ion Implantation In a-SixC1−x:H Thin Films
In this paper we report results on the optoelectronic and structural properties of device-quality a-SixC1−x:H intrinsic films with energy gap of 1.94 eV and Urbach energy of 70 MeV, grown by PECVD of SiH4+CH4 Mix...
-
Article
Silicon Carbon Alloys Produced by VHF and Conventional PECVD. A Comparison of their Properties.
The Very High Frequency (70 MHz) PECVD has recently proven its ability to produce Amorphous silicon with high deposition rates (10 Å/s) without affecting the quality of the Material. A comparative study of the...
-
Article
Defect Distribution and Bonding Structure in High Band Gap a-Si1−xCx:H Films Deposited in H2
AMorphous silicon carbide films were deposited by the PECVD technique in SiH4+CH4 gas mixtures at various CH4 flow rates with and without H2 dilution of the reactive Mixture. A detailed analysis of defect distrib...
-
Article
Study on Structural, Electrical and Optical Properties of Microcrystalline Si:H and SiC:H Films
We report results on a study on μc-Si.H and μc-SiC:H films deposited by PECVD. The crystallinity fraction and the crystal sizes have been evaluated by X-ray diffractometry, Raman spectroscopy and Transmission ...
-
Article
Undoped and Phosphorus Doped µ-SiC:H Films: Investigation of Electrical Properties and Hall Effect
We have deposited by Plasma Enhanced Chemical Vapour Deposition (PECVD), under particular conditions of high H2 dilution and high power density, undoped and phosphorus doped μc-SiC:H films. We have obtained n-dop...
-
Article
Optimization of Optoelectronic Properties of a-SiC:H Films
Amorphous silicon carbide films have been deposited by PECVD in SiH4+CH4+H2 mixtures at different hydrogen dilutions. The optoelectronic properties of the films have been measured by transmittance-reflectance spe...
-
Article
Effects of Electrode Spacing and Hydrogen Dilution on a-SiC:H and a-Si:H Layers
A series of hydrogenated amorphous silicon carbide (a-Si1−xCx:H) films was deposited by rf glow discharge deposition using various pressures, electrode spacings and hydrogen dilution ratios. We found that improve...
-
Article
Characterization of the Structure of Carbon Material Through the sp3/sp2 Bonding Ratio Measurements
Hydrogenated amorphous carbon (a-C:H) films have been deposited by sputter assisted plasma chemical vapor deposition (CVD). The relative concentration of sp3 and sp2 hybridized carbon in samples is determined by ...
-
Article
Doped Amorphous and Microcrystalline Silicon Carbide as Wide Band-Gap Material
As a conclusion it can be deduced that in silicon-carbon alloys high optical band-gap can be achieved both in amorphous and in microcrystalline films. In amorphous films the high band-gap is coupled to a diffi...
-
Article
Structure and Morphology of μc-SiC:H Films Produced by Pecvd
Films of μc-SiC:H have been deposited in a conventional PECVD system in order to investigate their structural and morphological properties. They consist of a mixed phase of Si crystallites (50-200 Å), surround...
-
Article
Effect of Boron and Phosphorus Ion Implantation on a-SixC1-x:H Thin Films
Ion implantation of boron and phosphorus in device quality a-SixC1-x:H films deposited by Ultra High Vacuum Plasma Enhanced Chemical Vapor Deposition (UHV PECVD) has been performed. The effects of damage and of d...
-
Article
Effect of Plasma Treatment of the Tco on a-Si Solar Cell Performance
Single junction a-Si p-i-n solar cells have been deposited by an Ultra High Vacuum (UHV) Multichamber PECVD system reaching an efficiency of 10.1% over 0.1 cm2 and 9.7% over 1 cm2. The effect of hydrogen treatmen...
-
Article
Crystallization Processes in Amorphous Hydrogenated Silicon Based Alloys
Amorphous and microcrystalline films of silicon and silicon carbide have been deposited by means of PECVD at low substrate temperature (200°C), with reactive gases highly diluted in H2. Devices quality a-Si:H fil...
-
Article
Crystallinity and Optoelectronic Properties of μc-SiC:H
Samples of μc-Si1−xCx:H with different degree of crystallinity and different carbon content were deposited by Plasma Enhanced Chemical Vapor Deposition and characterized by means of optical, electrical and struct...
-
Article
Thermal and Mechanical Properties of Diamond-Like a-C:H Films
Diamond-like amorphous carbon and hydrogenated amorphous carbon films (DLC) prepared by rf sputtering have been characterized by means of measurements of optical gap, hardness and Young's modulus. Preliminary ...
-
Article
Influence of Carbon on Structural, Optical and Electrical Properties of Microcrystalline Silicon Carbide.
Microcrystalline films of SiC:H have been deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) of SiH4+CH4+H2 mixtures with high power density and high H2 dilution, at variable CH4/SiH4 ratios. Their el...
