Tuesday, March 1, 2011
No. 253: A new emitting material for organic electroluminescence, no rare metals are required (March 1, 2011)
A professor of Kyushu University developed a new emitting material for organic electroluminescence. The new material is totally made of organic substances. Because it does not contain any rare metals, the production cost is less than that of the existing materials that contain rare metals like iridium. Called PIC-TRZ, the new material is built by combining carbazole and triazine and expected to be the major player for the next-generation organic electroluminescence. It has the behavior to change the energy lost in radiation for luminescence to fluorescence. A thin film element built with this new organic material emits greenly with a wavelength about 500 nanometers if electric current is applied to it. Using the principle of thermal activation delayed fluorescence, the new material does not need rare metals like iridium and platinum as the existing organic electroluminescence does. The new material has such low luminance efficiency as several percents at the present stage, but luminance efficiency can be improved by changing the combinations of elements. The new material is very promising because it helps organic electroluminescence expand the applications to laser oscillation and large-area luminescence.