Recombination and Metastability in Amorphous Silicon and Silicon-Germanium Alloys: Final Subcontract Report, 1 February 1991 - 31 January 1994
Electroluminescence-spectra- and transient-current measurements were taken before and after light-soaking a-Si:H p-i-n structures. For the first time, we were able to distinguish between bulk- and junction-controlled recombination. We found that in buffered p-b-i-n structures, the main-band luminescence was more pronounced than that in simple p-i-n structures. The enhancement of the main-band luminescence relates with an increase of the open-circuit voltage. This is evidence that the recombination takes place near the p-i interface, and the quality of the p-i interface is very important in solar cell performance. We also found that for thick p-i-n cells ({ge}2 {mu}m), the luminescence contains more high-energy photons (1.1--1.2 eV) than does that for thin cells. Furthermore, the high-energy recombination is more efficient in creating metastable defects than is the low-energy recombination. Consequently, the thinner the i-layer, the less the light-induced effects. The results of repetition rate and reverse bias effects on forward-bias current imply that the junctions recover faster than the bulk when subjected to excess carriers caused by the bias. By including the coulomb interaction, we made progress on a microscopic model for radiative recombination.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE)
- DOE Contract Number:
- AC36-08GO28308
- OSTI ID:
- 10169782
- Report Number(s):
- NREL/TP-451-6491; ON: DE94011837; BR: WM1020000
- Resource Relation:
- Other Information: PBD: Jul 1994
- Country of Publication:
- United States
- Language:
- English
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Recombination and metastability in amorphous silicon and silicon germanium alloys. Annual subcontract report, 1 February 1991--31 January 1992
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Related Subjects
SILICON SOLAR CELLS
MATERIALS
SILICON
RECOMBINATION
SILICON ALLOYS
GERMANIUM ALLOYS
PROGRESS REPORT
AMORPHOUS STATE
METASTABLE STATES
FABRICATION
photovoltaics
solar cells
recombination
metastability
amorphous silicon
silicon-germanium
alloys
140501
360601
PHOTOVOLTAIC CONVERSION
PREPARATION AND MANUFACTURE