A solid-state cathode ray tube

A solid-state cathode ray tube has been developed by scientists at the Tokyo University of Agriculture and Technology. The CRT used in most television sets and computer monitors consists of a bulky box with a gun that shoots electrons (cathode rays) from a hot cathode through a vacuum toward a phosphor screen. The new vacuumless solid-state equivalent makes use of nanocrystalline porous silicon, in which electrons subjected to an electric field are accelerated to several eV by a multiple-tunneling cascade through the interfacial barriers between nanocrystallites. The energetic electrons then ballistically hit a luminescent organic film deposited on the silicon, resulting in uniform planar light emission. Nobuyoshi Koshida argues that the device, unlike other flat-panel luminescent display candidates, has all of the desirable technological features: It consumes little power, is silicon-based, produces a sharp picture, is scalable to large areas, responds quickly, is inexpensive because of its simple design, and...