The present invention demonstrates a newly designed and synthesized carbazole scaffold based electro-fluorescent emitter, 9-butyl-2,7-(2-(4-methoxyphenyl)ethynyl)-9H-carbazole (Cz(APhOMe).sub.2), for ultra-violet OLED. This novel emitter has showed a high quantum yield of .about.78%. By doping in a host light-emitting layer of an OLED, the Cz(APhOMe).sub.2 guest light-emitting material shows a UV light belong to the near-UV region with high external quantum efficiency. Most importantly, a variety of experiment results have proved that this UV light is a pure UV light having only one peak wavelength in the emission spectrum thereof. Ascertainably, this pure UV light can be applied in numerous applications, such as biological sensors chemical sensors, leakage detection in automobiles, crack detection in airplanes, high density information storage devices, water treatment for germicidal protection, forensic investigations, sanitation and sterilization, laboratory researches, food industries, and fraud detection. |