3,6-Di(9-carbazolyl)-9-(2-ethylhexyl)carbazole based single-layer blue organic light emitting diodes

The electroluminescent device ITO/CuI/3,6-di(9-carbazolyl)-9-(2-ethylhexyl)carbazole(TCz1)/Ca/Al in which TCz1 for the first time was used as the emitting layer, was fabricated by means of vacuum deposition. The device emits blue light with a peaks at 388 and 406 nm at 4.5 V, with high current efficiency values (11.5 cd/A) and external quantum efficiency (1.72%).

► The blue OLED based on non-doped film of TCz1 was fabricated.
► Electroluminescence spectrum is similar to photoluminescence spectrum.
► Device exhibit high current efficiency of 11.5 cd/A and EQE of 1.72%.