A hybrid white organic light-emitting diode with stable color and reduced efficiency roll-off by using a bipolar charge carrier switch

► External quantum efficiency increases from 13.4% at 100 cd/m2 to 13.7% at 1000 cd/m2. ► The CIE (0.43, 0.43) and CRI of 89 remain nearly unchanged. ► Mixed host and spacer are the key factors in improving the performance.