Solution-processed single-emitting-layer white organic light-emitting diodes based on small molecules with efficiency/CRI/color-stability trade-off

By doping blue, green and red dyes into a bipolar host system, a simple single-EML white organic light-emitting diode (WOLED) with efficiency and color-stability trade-off was achieved by solution process. The resulting WOLED shows high efficiency (i.e., 36.5 cd/A and 15.7% at 1141 cd/m(2)), reduced efficiency roll-off (i.e., critical current density jc is as high as 140 mA/cm(2)) and, especially, extremely stable electroluminescence spectra with a slight CIE coordinate variation of (0.404 ± 0.004, 0.436 ± 0.001). The superior performance of the WOLED is attributed to the effective suppression of exciton quenching and charge trapping in the bipolar EML.