Ten newly synthesized oxadiazole derivatives have been examined as the emitter in organic electroluminescence (EL) devices, and it has been found that eight compounds show blue fluorescence. Most of the EL devices that use the new oxadiazole derivatives have luminance above 100 cd/m2 at less than 20 V. Especially significant is the EL device with 1, 3-bis [5-(p-dimethylaminophenyl)-1, 3, 4-oxadiazol-2-yl] benzane (OXD-8) which yields bright blue emission having intensity of 1000 cd/m2. The stability of device performance has also been investigated; no remarkable change in the blue emission has been observed after 40 days' standing at ambient temperature. The durability of the blue EL device under continuous driving conditions is also examined. The luminance falls to half its initial level after 0.25 hours at room temperature. At the temperature of liquid nitrogen, however, only a 20% decrease from the initial luminance is found even after 5 hours' driving. One of the main causes of luminance reduction is assumed to be Joule heat in the EL devices.
|Number of pages||11|
|Publication status||Published - Jun 1992|
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