Electrical characterization of CdTe grain-boundary properties from as processed CdTe/CdS solar cells
- Colorado State Univ., Fort Collins, CO (United States)
- National Renewable Energy Lab., Golden, CO (United States)
- Colorado School of Mines, Golden, CO (United States)
An ability to liftoff or separate the thin-film polycrystalline CdTe from the CdS, without the use of chemical etches, has enabled direct electrical characterization of the as-processed CdTe near the CdTe/CdS heterointerface. The authors use this ability to understand how a back-contact, nitric-phosphoric (NP) etch affects the grain boundaries throughout the film. Quantitative determination of the grain-boundary barrier potentials and estimates of doping density near the grain perimeter are determined from theoretical fits to measurements of the current vs. temperature. Estimates of the bulk doping are determined from high-frequency resistivity measurements. The light and dark barrier potentials change after the NP etch, and the origin of this change is postulated. Also, a variable doping density within the grains of non-etched material has been determined. These results allow a semi-quantitative grain-boundary band diagram to be drawn that should aid in determining more accurate two-dimensional models for polycrystalline CdTe solar cells.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC36-83CH10093
- OSTI ID:
- 305642
- Report Number(s):
- NREL/TP-520-25101; CONF-980735-PROC.; ON: DE98007497; TRN: IM9906%%322
- Resource Relation:
- Conference: 2. world conference and exhibition on photovoltaic solar energy conversion, Vienna (Austria), 6-10 Jul 1998; Other Information: PBD: Sep 1998; Related Information: Is Part Of NCPV preprints for the 2. world conference on photovoltaic solar energy conversion; PB: 142 p.
- Country of Publication:
- United States
- Language:
- English
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