United Solar Systems Corp. is an American joint venture solar cell manufacturing company based in Troy, MI. The company was formed in 1990 by Energy Conversion Devices, Inc., and Canon Inc. United Solar's unique thin-film solar cell technology achieves unprecedented levels of efficiency for amorphous silicon solar cells through the use of proprietary triple-junction spectrum-splitting cell design. Its advanced roll-to-roll manufacturing process uses a flexible stainless steel substrate that enables low-cost production and the development of many types of light-weight, robust, flexible and rigid solar cell modules.