ABSTRACT
Acknowledgment................................................................................................................. 36
References ........................................................................................................................... 36
The electroluminescence (EL) phenomenon was first discovered in a piece of carborundum
(SiC) crystal by H.J. Round in 1907 [1]. Commercial research into light-emitting diodes
(LEDs) technology started in early 1962, when Nick Holonyak Jr. created the first inorganic
LED [2,3]. Work on gallium arsenide phosphide (GaAsP) led to the introduction of the first
commercially mass-produced 655 nm red LEDs in 1968 by Hewlett-Packard and Monsanto.
In 1950s, Bernanose first observed EL in organic material by applying a high-voltage
alternating current (AC) field to crystalline thin films of acridine orange and quinacrine
[4,5]. The direct current (DC) driven EL cell using single crystals of anthracene was first
demonstrated by Pope and his coworkers following the discovery of LEDs made with III-V
compound semiconductors [6]. In 1975, the first organic electroluminescence (OEL) devices
made with a polymer polyvinyl carbazole (PVK) were demonstrated [7].
