Aging behavior of Au-based ohmic contacts to GaAs. Final contractor report

Technical Report · Fri Jul 01 00:00:00 EDT 1988

OSTI ID:6753838

Fatemi, N S

Gold based alloys, commonly used as ohmic contacts for solar cells, are known to react readily with GaAs. It is shown that the contact interaction with the underlying GaAs can continue even at room temperature upon aging, altering both the electrical characteristics of the contacts and the nearby pn junction. Au-Ge-Ni as-deposited (no heat treatment) contacts made to thin emitter (0.15 micrometer) GaAs diodes have shown severe shunting of the pn junction upon aging for several months at room temperature. The heat-treated contacts, despite showing degradation in contact resistance did not affect the underlying pn junction. Au-Zn-Au contacts to p-GaAs emitter (0.2 micrometer) diodes, however, showed slight improvement in contact resistance upon 200 C isothermal annealing for several months, without degrading the pn junction. The effect of aging on electrical characteristics of the as-deposited and heat-treated contacts and the nearby pn junction, as well as on the surface morphology of the contacts are presented.

• Research Organization: Sverdrup Technology, Inc., Cleveland, OH (USA)
• OSTI ID: 6753838
• Report Number(s): N-88-25831; NASA-CR-182146; E-4171; NAS-1.26:182146
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
GALLIUM ARSENIDE SOLAR CELLS
ELECTRIC CONTACTS
GOLD BASE ALLOYS
AGING
ANNEALING
CHEMICAL REACTIONS
DEPOSITION
EXPERIMENTAL DATA
GERMANIUM ALLOYS
NICKEL ALLOYS
P-N JUNCTIONS
ZINC ALLOYS
ALLOYS
DATA
DIRECT ENERGY CONVERTERS
ELECTRICAL EQUIPMENT
EQUIPMENT
GOLD ALLOYS
HEAT TREATMENTS
INFORMATION
JUNCTIONS
NUMERICAL DATA
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
SEMICONDUCTOR JUNCTIONS
SOLAR CELLS
SOLAR EQUIPMENT
140501* - Solar Energy Conversion- Photovoltaic Conversion