[Fabrication and analysis of the organic light-emitting diode with liquid host material]

An organic light-emitting diode (OLED) with a liquid host of 9-(2-ethylhexyl) carbazole (EHCz) doped with a guest dye of 5,6,11,12-tetraphenylnapthacene (rubrene) was demonstrated. Here the poly(3,4-ethylenedioxy thiophene):poly (styrenesulphonate) (PEDOT:PSS) and Cs2 CO3 were served as the hole injection material and electron injection material, respectively. The device structure consists of ITO/PEDOT:PSS/EH Cz:rubrene/Cs2CO3/ITO. Electroluminescence from rubrene with the highest external quantum efficiency of 0.03% at 0.26 mA cm(-2) was obtained. The photoluminescence (PL) and PL quantum efficiency of the materials were further studied.