A Solid State Cathode Ray Tube

A solid state cathode ray tube has been made by scientists at Tokyo University of Agriculture and Technology. Old CRTs, the kind generally used in TV and computer monitors, consist of bulky boxes containing guns shooting electrons from a hot cathode (cathode rays) at a phosphor screen. In the solid state equivalent electrons move ballistically (in straight lines) through a cascade of porous silicon nanocrystallites. Moreover, in this setup electrons move perpendicular to the device surface and are generated so that they strike linear arrays of phosphor pixels, resulting in truly planar emission of light. Nobuyoshi Koshida argues that his device, unlike other candidate flat-panel luminescent displays, possesses all of these important features: it consumes little power, is silicon-based, produces a sharp picture, is scalable to large areas, responds quickly, and is cheap because of its simple design. (Nakajima et al., Applied Physics Letters, 23 Sept; contact Nobuyoshi Koshida, 81-042-388-7128, koshida@cc.tuat.ac.jp; also see experimenter's website.)