Studies on Relative Effects of Charged and Neutral Defects in Hydrogenated Amorphous Silicon, Final Report, 1 October 1989 - 30 December 1990
This report covers the third year of a continuing research study to understand the relative importance of charged and neutral defects in amorphous silicon. The objective of the study is to explore the electronic structure, including neutral and charged defects, an optoelectronic effects including the formation of Staebler-Wronski defects. The study concentrated on exploring electroluminescence experimentally and interpreting the results employing a simple guiding model. The simple guiding model assumes an exponential density of states and recombination rate constants (radiative and non-radiative) which are governed by hopping transitions. Measurements were also made as a function of photodegradation of the material. The results implicate that the radiative recombination processes are not distant pair tunneling but rather results from electrons hopping down due to the coulomb interactions. Preliminary experiments have been made on the effect of photodegradation on transient space charge limited currents in n/i/n structures. These experiments can directly yield information on the occupied defects centers induced by the photodegradation and are not a result of recombination processes. To date the results seems to be consistent with a picture which places the doubly occupied defects at quite a high energy ({approx equal} 0.4 e.v. below the conduction band).
- 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:
- 5860672
- Report Number(s):
- NREL/TP-451-4691; ON: DE92001212
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SILICON
ELECTRONIC STRUCTURE
AMORPHOUS STATE
DEFECTS
ELECTROLUMINESCENCE
MATHEMATICAL MODELS
PROGRESS REPORT
SILICON SOLAR CELLS
SPACE CHARGE
DIRECT ENERGY CONVERTERS
DOCUMENT TYPES
ELEMENTS
EQUIPMENT
LUMINESCENCE
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
SEMIMETALS
SOLAR CELLS
SOLAR EQUIPMENT
photovoltaics
solar cells
amorphous silicon
defects
140501* - Solar Energy Conversion- Photovoltaic Conversion
665000 - Physics of Condensed Matter- (1992-)
360606 - Other Materials- Physical Properties- (1992-)