Although OLEDs are often viewed as being a modern technology, their development is based on pioneering work dating back to the 1950-60's.
Electrically stimulated emission of light, referred to as electroluminesncence (EL), was first reported in 1953 by A. Bernanose, M. Comte, and P. Vonaux [J. Chim. Phys. 50, 64 (1953)], using a high-voltage AC electrical field. M. Pope et al. at New York University conducted numerous studies on organic EL throughout the 1960’s and reported the first example of DC driven organic EL in 1963 [J. Chem. Phys. 38, 2042 (1963)].
Two years later in 1965 the first organic EL device based on carrier recombination—the same operating mechanism used in all modern LEDs and OLEDs—was reported by W. Helfrich and W.G. Schneider at the National Research Council of Canada [Phys. Rev. Lett. 14, 229 (1965) ]. Numerous patents pertaining to organic EL were also filed in the same time period, with the first patent being filed in 1960 by The Dow Chemical Company [US 3,172,862].
In these early days primitive sample preparation techniques, poor quality electrode contacts, and the low purity of the organic materials used were largely responsible for the inferior performance of early devices and the high operting voltages required (typically 100’s of volts to >1000 V in some cases).