tuhin4u (Unstopable Lover + Mariana World DIAMOND member): Also in 1965, W. Helfrich and W. G. Schneider of the National Research Council in Canada produced double injection recombination electroluminescence for the first time in an anthracene single crystal using hole and electron injecting electrodes, the forerunner of modern double injection devices. *05-10-14 - 05:02:37
tuhin4u (Unstopable Lover + Mariana World DIAMOND member): In the same year, Dow Chemical researchers patented a method of preparing electroluminescent cells using high voltage (500–1500 V) AC- driven (100–3000 Hz) electrically insulated one millimetre thin layers of a melted phosphor consisting of ground anthracene powder, tetracene, and graphite powder. *05-10-14 - 05:03:32
tuhin4u (Unstopable Lover + Mariana World DIAMOND member): Electroluminescence from polymer films was first observed by Roger Partridge at the National Physical Laboratory in the United Kingdom. The device consisted of a film of poly( n- vinylcarbazole) up to 2.2 micrometres thick located between two charge injecting electrodes. The results of the project were patented in 1975 and published in 1983. *05-10-14 - 05:05:20
tuhin4u (Unstopable Lover + Mariana World DIAMOND member): The first diode device was reported at Eastman Kodak by Ching W. Tang and Steven Van Slyke in 1987. This device used a novel two-layer structure with separate hole transporting and electron transporting layers such that recombination and light emission occurred in the middle of the organic layer; this resulted in a reduction in operating voltage and improvements in efficiency that led to the current era of OLED research and device production. *05-10-14 - 05:06:35
tuhin4u (Unstopable Lover + Mariana World DIAMOND member): Research into polymer electroluminescence culminated in 1990 with J. H. Burroughes et al. at the Cavendish Laboratory in Cambridge reporting a high efficiency green light-emitting polymer based device using 100 nm thick films of poly(p- phenylene vinylene). *05-10-14 - 05:07:38