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 can easily incorporate the three primary colors. (Y. Nakajima, A. Kojima, N. Koshida, Appl. Phys. Lett. 81 , 2472, 2002 http://dx.doi.org/10.1063/1.1508165 .)