Red Organic Light-Emitting-Diodes based on a N-Annulated Perylene Diimide Dimer
In this contribution we report on solution processed red OLEDs based upon a N-annulated perylene diimide dimer, namely tPDI2N-EH, a red-light emitting molecule. OLED devices with the architecture of glass/ITO/PEDOT:PSS/EML/LiF/Ag (EML = emitting layer) were fabricated with EMLs comprised of tPDI2N-EH neat and blended with poly (9,9-dicotylfluorene, PFO), all solution processed from non-halogenated solvents. The photophysical and electrophysical performance of PFO:tPDI2N-EH-blend films with different composition ratios were investigated. The PFO:tPDI2N-EH-based OLEDs with a 2:18 ratio exhibited best performance. The PFO:tPDI2N-EH-based OLEDs gave red electroluminescence with the emission wavelength of 635 nm and the CIE (international commission on illumination) coordinates of (x = 0.672, y = 0.321). OLEDs with EMLs fabricated using roll-to-roll compatible methods are also demonstrated.