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The effect of initial film composition and substrate in the sulfurization of CuInSe 2 was investigated. CuInSe 2 films deposited on either soda-lime glass (SL) or Corning 7059 ® borosilicate glass (7059) substrates were reacted in flowing H 2 S for times from 1 to 8 hours. Films with Cu-rich composition, Cu/In > 1, reacted for 1 hour had nearly all the Se replaced by S. For Cu-poor films the incorporation of S was significantly reduced. In addition, in Cu-poor films on SL glass CuInS 2 and NaInS 2 were found at the film surface. These phases were not detected in films on 7059 substrates or in Cu-rich films. A phenomenological model is proposed to explain the formation of segregated surface phases in Cu-poor films on SL substrates.

A reactive sputtering process was developed for the production of Cu(In,Ga)Se2 films on a moving stainless steel substrate, in simulation of the operation of a roll coater. Cu, In and Ga fluxes were provided through magnetron sputtering and were reacted in a flux of Se on the heated substrate. CdS films were deposited either by chemical bath deposition (CBD) or by sputtering. Devices of the type steel/Cr/Mo/CIGS/CdS/ZnO/Ag were completed by sputtering ZnO layers and by screen printing grid lines. We made devices with efficiency values above 9%. A uniformity study was performed on a CIGS film and on small area devices made from it. The target length was 12”. Targets of this size are expected to produce a uniformly thick deposit over a range of 6-8”. The film thickness was 2.54 μm over a range of 6” with a standard deviation ó of 0.04 μm. The film composition was uniform over a range of 16”. The values of Cu/III and Ga/III were 0.84 and 0.31, with ó values of 0.02 and 0.01, respectively. The efficiency of allsputtered devices was uniform over a range of 12”, well beyond the 6” wide range of constant CIGS film thickness. Their efficiency was 6.6% on average with ó=0.6%.

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