Original Article:
Highly efficient charge generation and injection in HAT-CN/TAPC heterojunction for high efficiency tandem organic light-emitting diodes
Jiakun Yuan, et al.
Organic Electronics, 2020, 83, 105745.
10.1016/j.orgel.2020.105745
Compared with single-unit OLEDs, charge generation layers (CGLs) can achieve higher brightness at low current densities, thereby greatly improving the efficiency and lifetime of fabricated OLEDs. So far, various CGLs have been reported, including organo-metal bilayers, metal-metal (or metal oxide) bilayers, and organic heterojunctions (OHJs). Studies have shown that OHJs can replace metal electrodes as charge injectors to achieve efficient injection of electrons and holes. OHJs should be preferred as CGLs due to their low evaporation temperature, high transmittance, facile preparation, and efficient charge generation capability.
In this work, the authors used the undoped planar OHJ of HATCN/TAPC to simultaneously serve as the intermediate CGL and charge injectors on both sides of the anode and cathode to fabricate high-performance tandem OLEDs. Among them, HATCN (Hexaazatriphenylenehexacabonitrile) has a deeper LUMO energy level, and it is easy to form effective charge transfer with the hole transport material TAPC whose HOMO energy level is close to the LUMO energy level of HATCN, ensuring effective charge generation. Finally, red, orange, green, and blue tandem OLEDs based on HAT-CN/TAPC OHJ as CGL and charge injector were fabricated. The results show that not only the EL efficiency but also the lifetime of the resulting tandem OLEDs are greatly improved.
Chemicals Related in the Paper:
| Catalog Number | Product Name | Structure | CAS Number | Price |
|---|---|---|---|---|
| ACM105598274-4 | Hexaazatriphenylenehexacabonitrile |  |
105598-27-4 | Price |
