Samsung Group, South Korea's biggest conglomerate, plans to open its new research and development complex for electronic materials next week in a city south of Seoul, industry sources said Sunday. According to the sources, the R&D center completed 22 months after it broke ground in January 2012, was jointly invested by five of the group's subsidiaries -- Samsung Electronics Co., Samsung SDI Co., Cheil Industries Inc., Samsung Fine Chemicals Co. and Samsung Corning Precision Materials Co.