Thin-film gallium arsenide solar-cell research. Annual project report, March 1, 1980-February 28, 1981

Technical Report · Sun Mar 01 00:00:00 EST 1981

DOI:https://doi.org/10.2172/6479175· OSTI ID:6479175

Chu, S. S.

The optimization of the deposition of gallium arsenide films of 10 ..mu..m thickness or less has been carried out with the objective of obtaining gallium arsenide films with uniform microstructure and good electrical properties. Gallium arsenide films of 10 ..mu..m or less thickness deposited on tungsten/graphite substrates exhibit, in most cases, pronounced shunting effects in large area MOS solar cells due to grain boundaries. The effective passivation of grain boundaries is necessary to produce solar cells with good conversion efficiency. Different grain boundary passivation techniques have been investigated to determine their effectiveness for large area solar cells from the deposited gallium arsenide films. The combination of ruthenium treatment and thermal oxidation has been shown to be the most effective passivation technique for large area MOS solar cells. MOS solar cells have been fabricated from gallium arsenide films of 10 ..mu..m thickness. The gallium arsenide films were treated with ruthenium ion and followed by thermal oxidation. The solar cells are of the configuration TiO/sub 2//Ag(grid contact)/Au/oxide/n-GaAs/n/sup +/-GaAs/W/graphite. MOS solar cells of 9 cm/sup 2/ area with an AM1 efficiency of up to 8.5% have been prepared reproducibly. The fabrication and characterization of thin film gallium arsenide homojunction solar cells have been initiated. The p/sup +/-n junction was formed in-situ by depositing the Zn-doped p/sup +/-layer immediately after the deposition of n/n/sup +/-layers. Without any surface passivation treatment, solar cells of 8 cm/sup 2/ area with an AM1 efficiency of about 7% have been prepared. With proper optimization in the fabrication processes, the conversion efficiency should be greatly improved. Therefore homojunction structure is a promising approach for the fabrication of thin film gallium arsenide solar cells.

• Research Organization: Southern Methodist Univ., Dallas, TX (USA)
• DOE Contract Number: AC02-77CH00178
• OSTI ID: 6479175
• Report Number(s): SERI/TR-9002-3-T2
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
GALLIUM ARSENIDE SOLAR CELLS
ELECTRICAL PROPERTIES
FABRICATION
GALLIUM ARSENIDES
DEPOSITION
TANTALUM OXIDES
SPUTTERING
ANTIREFLECTION COATINGS
EFFICIENCY
FILMS
GRAIN BOUNDARIES
GRAIN SIZE
MOS TRANSISTORS
OPTIMIZATION
ORGANOMETALLIC COMPOUNDS
OXIDATION
P-N JUNCTIONS
PASSIVATION
POLYCRYSTALS
RUTHENIUM IONS
SCANNING ELECTRON MICROSCOPY
SCHOTTKY BARRIER DIODES
SPECTRAL RESPONSE
ARSENIC COMPOUNDS
ARSENIDES
CHALCOGENIDES
CHARGED PARTICLES
CHEMICAL REACTIONS
COATINGS
CRYSTAL STRUCTURE
CRYSTALS
DIRECT ENERGY CONVERTERS
ELECTRON MICROSCOPY
EQUIPMENT
GALLIUM COMPOUNDS
IONS
JUNCTIONS
MICROSCOPY
MICROSTRUCTURE
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
PNICTIDES
SEMICONDUCTOR DEVICES
SEMICONDUCTOR DIODES
SEMICONDUCTOR JUNCTIONS
SIZE
SOLAR CELLS
SOLAR EQUIPMENT
TANTALUM COMPOUNDS
TRANSISTORS
TRANSITION ELEMENT COMPOUNDS
140501* - Solar Energy Conversion- Photovoltaic Conversion
360601 - Other Materials- Preparation & Manufacture