Optimization of transparent electrode for solar cells. Final technical report, September 15, 1980-September 14, 1981

Technical Report · Thu Jan 01 00:00:00 EST 1981

OSTI ID:6121647

Gordon, R G

Solar cells convert sunlight into either electricity or chemicals (including fuels, such as hydrogen). In order to carry out these conversions efficiently, solar cells usually need a surface layer which simultaneously transmits almost all of the incident sunlight, and also conducts electricity very well. Such layers, called transparent electrodes, must also be strong, stable to weathering and sunlight, inexpensive, non-toxic, non-polluting, and composed of sufficiently abundant materials. This long list of requirements is best met by a film of tin oxide made by a new process. The research had as its goal further improvements in the properties of this transparent electrode material. The first phase of the work developed reliable methods for optical and electrical evaluation of the films and a figure of merit (FOM) evaluating the quality of the material as a transparent electrode. Impurities introduced from the chemical reagents were shown to be unimportant in limiting the FOM. However, alkali impurities introduced from high-alkali glass substrates may be significant, and this effect requires further study. The FOM increases with increasing substrate temperature and decreasing tetramethyltin concentration. The dependence on fluorine dopant concentration is more complicated, and there may be two distinct optimum regions. Typical films now have 6% absorption for a sheet resistance of 6 ohms per square, and some further improvements are expected with more complete optimization.

• Research Organization: Harvard Univ., Cambridge, MA (USA)
• DOE Contract Number: AC02-77CH00178
• OSTI ID: 6121647
• Report Number(s): SERI/TR-9318-1-T3; ON: DE82002029
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
SOLAR CELLS
COATINGS
ELECTRODES
TIN OXIDES
ABSORPTIVITY
CHEMICAL VAPOR DEPOSITION
ELECTRIC CONDUCTIVITY
FILMS
FLUORINE
IMPURITIES
LIGHT TRANSMISSION
OPTIMIZATION
CHALCOGENIDES
CHEMICAL COATING
DEPOSITION
DIRECT ENERGY CONVERTERS
ELECTRICAL PROPERTIES
ELEMENTS
EQUIPMENT
HALOGENS
NONMETALS
OPTICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
SOLAR EQUIPMENT
SURFACE COATING
TIN COMPOUNDS
140501* - Solar Energy Conversion- Photovoltaic Conversion