History

Although the property of elettroluminescenza possessed from some organic elements is known gives along time, the first types of display OLED never did not go beyond the prototype stage, in how much demanded too much high tensions of feeding (beyond 100 V) in order to turn out useful in the practical applications. Subsequently, they were developed with succeeding thin films of elettroluminescente organic material, whose small dimensions allowed the feeding through more modest tensions.
The first using models of display this technology were structurally much simple: a film of organic substance was placed between two electrodes (anode and cathode): applying a tension to the two electrodes, the passage of current in the organic layer of it caused the luminous emission.
However, this type of electrodes was not much practical one, in how much demanded, in order to work, an extreme precision in phase of production; a not perfect alignment, in fact, caused to great losses of energy and consequent inefficiency of the display.

The first display efficient ones and to low tension were introduce to you in the 1987 from Ching Tang and Steve Van Slyke; such display they made use of two organic layers: one predisposed in order to receive gaps, the other in order to receive electrons; in this way, and with successes improvements, volt was possible to construct to you display to high brightness feeds to you from low tensions (approximately 10).