In earlier research, conversion efficiency of 10.4% (AM1.5) and 9.9% (AM0) has been achieved on small area CuInxGa1-xS2 (CIGS2) solar cell on 127 mum thick stainless steel substrate. The area of research is mainly focused on studying CIGS2 thin films as solar cell absorber material and growing high efficiency cells on ultralightweight and flexible metallic foils such as 127 mum thick stainless steel and SiO2 coated 25 mum thick Ti foils. This paper presents the scaling up process of CIGS2 thin film substrate from 2.5 x 2.5 cm(2) to 10 x 10 cm(2). Initial scaling up efforts focused on achieving uniform thickness and stress-free films. Process of scaling up consisted of refurbishment of selenization/sulfurization furnace, design and fabrication of scrubber and enlargement of new CdS deposition setup. The scaling up from 2.5 x 2.5 cm(2) to 10 x 10 cm(2) substrate size has laid the foundation for PV Materials Lab of Florida Solar Energy Center becoming the nucleus of a pilot plant. (C) 2004 Elsevier Ltd. All rights reserved.