Highly Efficient Multi-Functional Material for Organic Light-Emitting Diodes;

We have demonstrated that TPyPA can be used as an efficient multi-functional material for OLEDs; hole transporting material (HTL), blue and white-light emitter. The device based on TPyPA as the HTL exhibited an external quantum efficiency of 1.7 % and a luminance efficiency of 4.2 cd/A; these values are 40 % higher than the external quantum efficiency and luminance efficiency of the NPD-based reference device. The device based on TPyPA as a blue-light emitter exhibited an external quantum efficiency of 4.2 % and a luminance efficiency of 5.3 cdA–1 with CIE coordinates at (0.16, 0.14), the device based on TPyPA as a white-light emitter exhibited an external quantum efficiency of 3.2 % and a luminance efficiency of 7.7 cdA–1 with CIE coordinates at (0.33, 0.39). Also, TPyPA-based organic solar cell (OSC) exhibited a maximum power conversion efficiency of 0.35%. TPyPA-based organic thin-film transistors (OTFTs) exhibited highly efficient field-effect mobility (µFET) of 1.7 × 10 –4 cm2 V–1 s–1, a threshold voltage (Vth) of –15.9 V, and an on/off current ratio of 8.6 × 1