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From: Kevin.Dowling%CMU-RI-ROVER@sri-unix.UUCP
Newsgroups: net.space
Subject: PV Cell efficiency
Message-ID: <13538@sri-arpa.UUCP>
Date: Thu, 10-Nov-83 15:43:37 EST
Article-I.D.: sri-arpa.13538
Posted: Thu Nov 10 15:43:37 1983
Date-Received: Sun, 13-Nov-83 17:02:24 EST
Lines: 13

Reported in latest Laser Focus and EOSD:
	Spire Corp. has developed a process for growing a thin film of
Ga-As directly on a silicon substrate. The process converts a conventional
single band-gap Si cell with a typical efficiency of 12% to a two band-gap
cell with a theoretical efficiency of 30% and a likelyconversion rate
of 25% in large scale production. In solar cell application, Si is lower
in cost but GaAs is more efficient because it captures a larger portion
of the solar spectrum. The blurb (in the postdeadline reports section)
goes on to mention that the method is a metalorganic chemical vapor
process that allow extremely precise deposition of the GaAs.
At a production level of 1MW per year, this photovoltaic process is estimated
to add $1.30/W to cell costs; at 50MW/year, only $0.22/W. Cell effficiency
will thus be more than doubled.