High Efficiency Cadmium and Zinc Telluride-Based Thin Film Solar Cells, Final Subcontract Report, 1 March 1989 - 28 February 1990

Technical Report · Mon Oct 01 04:00:00 EDT 1990

DOI:https://doi.org/10.2172/6494780· OSTI ID:6494780

Rohatgi, A.; Summers, C. J.; Erbil, A.; Sudharsanan, R.; Ringel, S.

Polycrystalline Cd{sub 1-x}Zn{sub x}Te and Cd{sub 1-x}Mn{sub x}Te films with a band gap of 1.7 eV were successfully grown on glass/SnO{sub 2}/CdS substrates by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD), respectively. Polycrystalline Cd{sub 1-x}Zn{sub x}Te films grown by MBE resulted in uniform composition and sharp interfaces. However, polycrystalline Cd{sub 1-x}Mn{sub x}Te films grown by MOCVD showed nonuniform compositions and evidence of manganese accumulation at the Cd{sub 1-x}Mn{sub x}Te/CdS interface. We found that manganese interdiffuses and replaces cadmium in the CdS film. By improving the CdTe/CdS interface and, thus, reducing the collection function effects, the efficiency of the MOCVD CdTe cell can be improved to about 13.5%. MBE-grown CdTe cells also produced 8%--9% efficiencies. The standard CdTe process was not optimum for ternary films and resulted in a decrease in the band gap. Recent results indicate that CdCl{sub 2} + ZnCl{sub 2} chemical treatment may prevent the band-gap reduction, and that chromate etch (rather than bromine etch) may provide the solution to contact resistance in the ternary cells.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 6494780
• Report Number(s): SERI/TP-211-3952; ON: DE91002112
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
360601 -- Other Materials-- Preparation & Manufacture
CADMIUM TELLURIDE SOLAR CELLS
CHALCOGENIDES
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
CONVERSION
CRYSTAL GROWTH
DEPOSITION
DIRECT ENERGY CONVERSION
DIRECT ENERGY CONVERTERS
DOCUMENT TYPES
EFFICIENCY
ENERGY CONVERSION
EPITAXY
EQUIPMENT
FABRICATION
FILMS
GRADED BAND GAPS
MANGANESE COMPOUNDS
MANGANESE TELLURIDES
MOLECULAR BEAM EPITAXY
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHOTOVOLTAIC CONVERSION
PROGRESS REPORT
SOLAR CELLS
SOLAR EQUIPMENT
SUBSTRATES
SURFACE COATING
TELLURIDES
TELLURIUM COMPOUNDS
THIN FILMS
TIN COMPOUNDS
TIN OXIDES
TRANSITION ELEMENT COMPOUNDS
ZINC COMPOUNDS
ZINC TELLURIDES
cadmium telluride
photovoltaics
solar cells
thin films