Samsung SDI was established in 1970, starting out as a display maker - making CRTs, LCDs and PDP panels. The company handled Samsung's OLED business but in 2008 Samsung Mobile Display was spun off to handle all of Samsung's mobile display (this was later merged into Samsung Display). Samsung SDI changed its focus to renewable energy (mostly L-ion batteries).
In March 2014, Samsung SDI acquired Samsung's Cheil Industries for $3.3 billion who's involved with electronic materials - including OLED materials. In August 2013, Cheil Industries (together with Samsung Electronics) acquired Novaled for €260 million. So Samsung SDI is now involved with OLED materials and is a major stakeholder in Novaled.