Question

Explain the 3 Emissive flat-panel devices: electroluminescent, plasma display and field-emission display with detail to the use of phosfur if used

Answer 1

Electroluminescent Display

An electroluminescent screen is a flat screen that is made by sandwiching a layer of electroluminescent material between two conductive layers. When a current is circulated on the material, it emits radiation in the form of visible light. Electroluminescence is an optical and electrical phenomenon in which light is generated from an electric current. Electroluminescent materials contain a certain amount of phosphor material and emit light when an electric current passes (do not confuse phosphur with the chemical element phosphorus). Phosphur are electroluminescent and are not necessarily composed of the phosphor element. Phosphur materials contain a carrier material such as: oxides, oxynitrides, nitrides, sulfur, among others, which are doped with small amounts of rare earths or transition metal ions.

plasma display

Plasma screens are devices formed by glass panels divided into cells and containing a mixture of noble gases that when excited by electricity, become plasma (hence the name) and phosphur materials begin to emit light. Plasma screens are also formed by pixels, where each pixel has three separate cells in which there is different colored phosphur material: red, blue and green, where they are mixed to create the final color of the pixel.

field-emission display

A field emission screen is a flat screen technology that uses large area electron emission sources to provide electrons that strike the phosphur material to produce a color image. An field-emission display consists of a matrix of cathode ray tubes, where each tube produces a subpixel grouped three by three to form red-green-blue RGB pixels. The field-emission display combine the advantages of CRTs, that is, high contrast levels and rapid response tempos, with the advantage of packaged LCD.