Fig. 1. Energy-level structure of device (symbols of ‘h+’ and ‘e-’ represent hole and electron, respectively)

Fig. 2. Performances of TXO-PhCz doped CzSi single-emitting layer devices with different concentrations. (a) Relationship among voltage, brightness, and current density; (b) relationship among current density, current efficiency, and power efficiency

Fig. 3. Performances of TXO-PhCz doped Tm3PyP26PyB single-emitting layer devices with different concentrations. (a) Relationship among voltage, brightness, and current density; (b) relationship among current density, current efficiency, and power efficiency

Fig. 4. Diagrams of carrier injection and transmission of single-emitting layer devices. (a) Diagram of carrier injection and transmission of TXO-PhCz doped CzSi single-emitting layer device; (b) diagram of carrier injection and transmission of TXO-PhCz doped Tm3PyP26PyB single-emitting layer device

Fig. 5. Spectra of TXO-PhCz doped CzSi single-emitting layer devices with different concentrations

Fig. 6. Spectra of TXO-PhCz doped Tm3PyP26PyB single-emitting layer devices with different concentrations

Fig. 7. Performances of TXO-PhCz doped CzSi double-emitting layer devices with different concentrations. (a) Relationship among voltage, brightness, and current density; (b) relationship among current density, current efficiency, and power efficiency

Fig. 8. Performances of TXO-PhCz doped Tm3PyP26PyB double-emitting layer devices with different concentrations. (a) Relationship among voltage, brightness, and current density; (b) relationship among current density, current efficiency, and power efficiency

Fig. 9. Carrier diagrams of double-emitting layer. (a) Carrier diagram of double-emitting layer using TcTa and CzSi as host materials; (b) carrier diagram of double-emitting layer using TcTa and Tm3PyP26PyB as host materials