Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Development of metallization for GaAs and AlGaAs concentrator solar cells

Technical Report ·
OSTI ID:6587144
A three-layer metallization system was developed for high temperature stability on GaAs and AlGaAs solar cells. The layers are a Pt ohmic contact metal that forms thermally stable compounds with GaAs, a TiN diffusion barrier, and a gold conductor. The solar cell structure was also designed for contact stability, with the key component being a heavily doped GaAs cap layer. Reactively sputtered TiN was found to act as an excellent barrier when deposited under the proper conditions. The conditions were carefully optimized for low resistivity and low stress in the films. A low but nonzero substrate bias during sputtering was found to be important. Solar cells with sputtered metallizations of Pt/TiN/Ti/Pt/Au were found to be thermally stable up to 500/sup 0/C for 15 minutes in vacuum. At 600/sup 0/C there was catastrophic degradation of the cells due to dissociation of uncapped GaAs surfaces. Below this temperature the metallization performed as designed. The Pt and GaAs layers reacted to form a stable PtGa compound layer that gave low contact resistance. There was no penetration of Au or GaAs through the barrier layer. These results are a very encouraging first step leading to stable, reliable GaAs and AlGaAs concentrator cells.
Research Organization:
Spire Corp., Bedford, MA (USA)
DOE Contract Number:
AC04-76DP00789
OSTI ID:
6587144
Report Number(s):
SAND-86-7052; ON: DE87007951
Country of Publication:
United States
Language:
English

Similar Records

Transfer of TiN/Ti/Ag metallization research
Technical Report · Thu May 01 00:00:00 EDT 1986 · OSTI ID:5838645

Metallization systems for stable ohmic contacts to GaAs
Technical Report · Mon Dec 31 23:00:00 EST 1984 · OSTI ID:5594672

Thin-film barriers
Technical Report · Sat Sep 01 00:00:00 EDT 1984 · OSTI ID:6509474