Blue organic light-emitting diode with an extremely small turn-on voltage

Reducing the driving voltage of blue organic light-emitting diodes (OLEDs) is an essential issue for saving display energy. In this study, a novel combination of blue-emitting material and electron transport material was discovered to realize upconversion emission through triplet-triplet annihilation near the interface. The blue OLED with an extremely small turn-on voltage of 1.47 V was developed.