Lockheed Martin Astronautics (LMA) has developed a large-area (30 x 30 cm) in-line, sequential CIS manufacturing approach amenable to low-cost photovoltaics (PV) production. A prototype CIS manufacturing system has been designed and built with compositional uniformity (Cu/ln ratio) verified within +/- 4 atomic percent over a 30 x 30 cm area. CIS (non Ga containing) device efficiencies have been measured by the National Renewable Energy Laboratory (NREL) at 7% on a flexible non-sodium-containing substrate and 10% on a soda-lime-silica glass substrate. Recent CIS effort has included Ga incorporation, with a goal of increasing the cell-level efficiency and modifying the bandgap to reduce module integration losses. Critical elements of the manufacturing capability include the sequential process selection, uniform large-area material deposition, and in situ process control. Details of the process and large-area manufacturing approach are discussed and results presented. (C) 1999 Published by Elsevier Science B.V. All rights reserved.
