Robert is CEO of RayVio, a solid state ultraviolet solutions company based in Silicon Valley. He is also an independent Board member of Pacific Light Technologies, which provides quantum dots for LED-based lighting and displays. From 2007-2012, he was a Partner at Sierra Ventures, a private venture capital firm that manages more than $1.5 billion of committed capital.

Dr. Walker focused on investments in solid state lighting, displays, clean technology, solar energy and semiconductors.