Highly efficient blue-green emission from organic light-emitting diodes using dibenzochrysene derivatives

We have fabricated highly efficient organic light-emitting diodes (OLEDs) u sing new hole-transporting emissive materials based on dibenzochrysene. Hol e drift mobilities of the dibenzochrysene derivatives were measured in the vacuum-deposited films and found to be 5 x 10(-4)-2 x 10(-3) cm(2)/V s (at 5 x 10(5) V/cm). The OLEDs consist of an emitting layer of the dibenzochrys ene derivative and an electron-transport layer of tris(8-quinolinolato) alu minum. Emission colors of the OLEDs were blue-green and their spectra were consistent with the photoluminescence spectra with a peak wavelength of 490 nm. High external quantum efficiency of 2% was obtained at a luminance of 300 cd/m(2), and good durability in a continuous operation at room temperat ure and high temperatures was achieved. (C) 2000 American Institute of Phys ics. [S0003-6951(00)02328-7].