Photoelectronic properties of II-VI heterojunctions. Progress report No. 2, April 1, 1977-February 28, 1978

Technical Report · Sun Jan 01 04:00:00 EST 1978

OSTI ID:6765850

Bube, R H

It is shown that ZnO thin films can be deposited either by rf sputtering or by spray pyrolysis and can be brought to the desired conductivity range for ZnO/CdTe heterojunction performance. First generation cells showed very high values of short-circuit current (19 mA/cm/sup 2/ for AM2 solar simulation); values of open-circuit voltage at least as large as 0.51 V have been obtained using ZnO films prepared by spray pyrolysis from ZnCl/sub 2/ solution. Solar efficiencies of 4.6% have been obtained in this preliminary research on the ZnO/CdTe cell. ITO/CdTe heterojunctions have been prepared by rf sputtering of ITO films; a solar efficiency of 8% was produced in the best cell corresponding to V/sub oc/ = 0.82 V and J/sub sc/ = 14.5 mA/cm/sup 2/. Initial transmission electron microscope pictures of ITO films have been made. ITO/CdTe cells exhibit degradation on heat treatment, and the mechanisms of degradation are of central interest. A correlation between Cu/sub 2/S/CdS heterojunction properties prepared on thin-film CdS with those prepared on single crystal CdS is under study. The preparation of indium-tin oxide films to be used as a back contact for the thin-film cells is discussed, and an apparatus is described for the preparation of both types of cells by the dry method, i.e., vacuum evaporation of CuCl followed by heat treatment to produce a Cu/sub 2/S/CdS junction. This method is much better suited than the dipping method for the comparison of thin-film and single crystal cells prepared under identical conditions. High quantum efficiency cells with open-circuit voltage in the 0.4 to 0.5 V range have been produced with single crystal substrates. (WHK)

• Research Organization: Stanford Univ., CA (USA). Dept. of Materials Science and Engineering
• DOE Contract Number: AT03-76ER70047
• OSTI ID: 6765850
• Report Number(s): SU-DMS-77-R-4
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
36 MATERIALS SCIENCE
360601 -- Other Materials-- Preparation & Manufacture
CADMIUM COMPOUNDS
CADMIUM SULFIDE SOLAR CELLS
CADMIUM SULFIDES
CADMIUM TELLURIDE SOLAR CELLS
CADMIUM TELLURIDES
CHALCOGENIDES
COATINGS
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER SULFIDES
CRYSTAL STRUCTURE
DEPOSITION
DIFFRACTION
DIP COATING
DIRECT ENERGY CONVERTERS
EFFICIENCY
ELECTRIC CONTACTS
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
ELECTRON DIFFRACTION
ELECTRON MICROSCOPY
ENERGY GAP
EQUIPMENT
FABRICATION
FILMS
HEAT TREATMENTS
INDIUM COMPOUNDS
INDIUM OXIDES
INORGANIC PHOSPHORS
JUNCTIONS
MICROSCOPY
MICROSTRUCTURE
OPTICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHOSPHORS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
SCATTERING
SEMICONDUCTOR JUNCTIONS
SOLAR CELLS
SOLAR EQUIPMENT
SPRAY COATING
SPRAYED COATINGS
SPUTTERING
SUBSTRATES
SULFIDES
SULFUR COMPOUNDS
SURFACE COATING
TELLURIDES
TELLURIUM COMPOUNDS
TIN COMPOUNDS
TIN OXIDES
TRANSITION ELEMENT COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY
ZINC COMPOUNDS
ZINC OXIDES