Preparation and characterization of hydrogenated amorphous-silicon films produced by ion plating and hydrogenated amorphous-boron films produced by glow-discharge decomposition. Final report, April 1, 1980-May 31, 1981

Technical Report · Sat Aug 01 04:00:00 EDT 1981

DOI:https://doi.org/10.2172/5962055· OSTI ID:5962055

Cocks, F. H.; Jones, P. L.

This program has had two main goals - the investigation of ion-plating as a novel means of a-Si:H film preparation and the evaluation of a-B:H as a candidate solar cell material. Substantial progress has been made in both areas. Co-evaporation doping of a-Si:H by Ga has been achieved, and it has been shown that Ga is a p-type dopant. The thermoelastic properties of a-Si:H have been determined. It has been shown to be possible to produce stress-free films of a-Si:H by the use of Invar substrates. Positron annihilation Doppler measurements of a-Si:H show a systematic decrease in line width as one proceeds from crystalline Si to a-Si to a-Si:H. Detailed studies of the optical band gap of a-B:H show that the band gap of this material may be controlled over the wide range from 0.9 to 2.2 eV. Samples of band gaps near 1.45 eV can be produced either by the use of post deposition heat-treatments (7 hours at 360/sup 0/C) or by the use of hot (350/sup 0/C) substrates during deposition. The band gap is a function of the B/H ratio, and it has also been possible to produce 1.45 eV band gap films through the use of BF/sub 3//B/sub 2//H/sub 6/ gas ratios of 8:1. These films can be doped n-type either by the use of C (as ethylene) or Si (as silane) additives to the BF/sub 3//B/sub 2/H/sub 6/ glow. Electron spin resonance measurements of such optimized films give evidence of fluorine as well as hydrogen incorporation into the films. The photoconductivity of a-B:H films is found to be sensitive to impurity contamination. In the best films, however, room temperature photoconductivities two orders greater than dark photoconductivities have been observed. The use of higher purity boron (99.9995%) as a cathode material for our DC glow is expected to improve this conductivity further.

• Research Organization: Duke Univ., Durham, NC (USA). Dept. of Mechanical Engineering and Materials Science
• DOE Contract Number: AC02-77CH00178
• OSTI ID: 5962055
• Report Number(s): SERI/TR-9054-1-T1; ON: DE81030276
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
ALLOYS
AMORPHOUS STATE
ANNIHILATION
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BASIC INTERACTIONS
BORON
CRYSTAL DOPING
DEPOSITION
DOPPLER BROADENING
ELASTICITY
ELECTRIC CONDUCTIVITY
ELECTRIC DISCHARGES
ELECTRICAL PROPERTIES
ELECTROMAGNETIC INTERACTIONS
ELECTRON SPIN RESONANCE
ELEMENTARY PARTICLES
ELEMENTS
ENERGY GAP
FERMIONS
FILMS
FLUORINE
GALLIUM ADDITIONS
GALLIUM ALLOYS
GLOW DISCHARGES
HALOGENS
HYDRIDES
HYDROGEN ADDITIONS
HYDROGEN COMPOUNDS
IMPLANTS
INTERACTIONS
INVAR
IRON ALLOYS
IRON BASE ALLOYS
LEPTONS
LINE BROADENING
MAGNETIC RESONANCE
MECHANICAL PROPERTIES
NICKEL ALLOYS
NONMETALS
OPTICAL PROPERTIES
PHOTOCONDUCTIVITY
PHYSICAL PROPERTIES
PLATING
POSITRONS
RESONANCE
SEMIMETALS
SILANES
SILICON
SILICON COMPOUNDS
STRESSES
SURFACE COATING
TENSILE PROPERTIES
THERMOELASTICITY
VAPOR PLATING
YOUNG MODULUS