Abstract
Highly efficient tandem organic light-emitting diodes (TOLEDs) were achieved based on a non-doped charge generation unit (CGU) consisting of LiF/Al/C60/4,4',4"-tris(N-3-methylphenyl-N-phenyl-amino) triphenylamine (m-MTDATA) and ultrathin emitting layers. The current-voltage characteristics of the CGU devices and electron-only devices and the capacitance-voltage characteristics of the CGU-based capacitance devices were characterized to explore the charge generation and injection mechanisms. The charge generation process occurs at the interface of C60/m-MTDATA through electron transferring from the highest occupied molecular orbital of m-MTDATA to the lowest unoccupied molecular orbital of C60. It is found that the thinner C60 layer contributes to efficient electron injection. Under the optimal structure, the blue TOLEDs exhibit a maximum current efficiency (CEmax) of 43.3 cd/A. The CEmax and maximum external quantum efficiency (EQEmax) of the white TOLEDs reach 84.6 cd/A and 26.7%, respectively.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.