By depositing thin films of silicon nanoparticles on silicon substrates, researchers at the University of Illinois at Urbana-Champaign have fabricated a photodetector sensitive to ultraviolet light. Silicon-based ultraviolet sensors could prove very handy in military, security and commercial applications.
''Silicon is the most common semiconductor, but it has not been useful for detecting ultraviolet light until now,'' said Munir Nayfeh, a professor of physics at Illinois and a researcher at the Beckman Institute for Advanced Science and Technology. ''Ultraviolet light is usually absorbed by silicon and converted into heat, but we found a way to make silicon devices that absorb ultraviolet light and produce electrical current instead.''