Studies of hydrogenated amorphous silicon
This report discusses the results of probing the defect structure and bonding of hydrogenated amorphous silicon films using both nuclear magnetic resonance (NMR) and electron spin resonance (ESR). The doping efficiency of boron in a-Si:H was found to be less than 1%, with 90% of the boron in a threefold coordinated state. On the other hand, phosphorus NMR chemical shift measurements yielded a ration of threefold to fourfold P sites of roughly 4 to 1. Various resonance lines were observed in heavily boron- and phosphorus-doped films and a-SiC:H alloys. These lines were attributed to band tail states on twofold coordinated silicon. In a-SiC:H films, a strong resonance was attributed to dangling bonds on carbon atoms. ESR measurements on low-pressure chemical-vapor-deposited (LPCVD) a-Si:H were performed on samples. The defect density in the bulk of the films was 10/sup 17//cc with a factor of 3 increase at the surface of the sample. The ESR spectrum of LPCVD-prepared films was not affected by prolonged exposure to strong light. Microcrystalline silicon samples were also examined. The phosphorus-doped films showed a strong signal from the crystalline material and no resonance from the amorphous matrix. This shows that phosphorus is incorporated in the crystals and is active as a dopant. No signal was recorded from the boron-doped films.
- Research Organization:
- Naval Research Lab. (NRL), Washington, DC (United States)
- DOE Contract Number:
- AC02-83CH10093
- OSTI ID:
- 6781663
- Report Number(s):
- SERI/STR-211-2393; ON: DE84013038
- Resource Relation:
- Other Information: Portions are illegible in microfiche products. Original copy available until stock is exhausted
- Country of Publication:
- United States
- Language:
- English
Similar Records
Detailed investigation of doping in hydrogenated amorphous silicon and germanium
Structural and electronic properties of amorphous-silicon-based alloy materials. Final report, June 1983-May 1984
Related Subjects
36 MATERIALS SCIENCE
SILICON
CRYSTAL DEFECTS
ELECTRON SPIN RESONANCE
NUCLEAR MAGNETIC RESONANCE
AMORPHOUS STATE
BORON
CHEMICAL VAPOR DEPOSITION
CRYSTAL DOPING
HYDROGEN ADDITIONS
PHOSPHORUS
CHEMICAL COATING
CRYSTAL STRUCTURE
DEPOSITION
ELEMENTS
MAGNETIC RESONANCE
NONMETALS
RESONANCE
SEMIMETALS
SURFACE COATING
SOLAR ENERGY
PHOTOVOLTAIC
140501* - Solar Energy Conversion- Photovoltaic Conversion
360603 - Materials- Properties