Bright, saturated, red-to-yellow organic light-emitting devices based on polarization-induced spectral shifts

We demonstrate red, orange, and yellow organic light-emitting devices (OLED) with the electroluminescent layer consisting of aluminum tris(8-hydroxyquinoline) (Alq3) doped with laser dye DCM2, with the emission color dependent on the concentration of DCM2. A peak emission wavelength shift of up to 50 nm is found to be due to strong polarization effects. For red and yellow–orange OLEDs, a maximum luminance of 1400 cd/m2 and 15200 cd/m2 is measured, with a luminance of 100 cd/m2 attained at 100 mA/cm2 (14 V) and 10 mA/cm2 (12 V), respectively. The current versus voltage dependencies of these devices are consistent with trap-limited conduction, unaffected by the presence of DCM2.