Thin films of amorphous diamondlike carbon (a:DLC) were deposited on G
aAs solar cells, with and without antireflecting coating. The films we
re deposited by decomposition of CH4 plasma using a r.f. generator (13
.56 MHz). The reflected light from these cells, in the visible light,
decreased after deposition of a:DLC film thickness (from 33% for t = 0
nm to 14% for r = 60 nm) which indicates antireflecting properties. T
he I-V measurements show an increase of the short circuit current (I-s
c) with films thickness up to t similar to 40-60 nm, where it reaches
a maximum and then decreases for higher thickness (r > 60 nm). The eff
iciency (eta) of the cells, as a function of the a:DLC thickness, show
s a maximum value of similar to 15% for t = 50 nm. It was also shown,
that the a:DLC films is a useful material as a protecting material for
cells for operation in an abrasive environment. In abrasive environme
nt, the efficiency of the coated cell maintains the level of about 12%
whereas the efficiency of uncoated cells drop sharply from 15.5% to 6
%. (C) 1998 Elsevier Science S.A. All rights reserved.