2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN) based fluorescent blue organic light-emitting diodes (OLEDs) are demonstrated. With MADN as emitting layer, experiments indicate that thick MADN (40–60 nm) is preferable for constructing efficient blue OLED. With MADN as hole-transport and emitting layer and tris(8-hydroxy-quinolinato)aluminium (Alq3) as electron-transport layer, the OLED electroluminescent characteristics show a mixture emission of MADN and Alq3 with Commission Internationale d'Eclairage (CIE) color coordinates of (0.25, 0.34), indicating feasible hole transporting in MADN. Using 4,7-diphenyl-1,10-phenanthroline (BPhen) replacing Alq3 as electron-transport layer, the OLED shows deep blue emission with a maximum luminous efficiency of 4.8 cd/A and CIE color coordinates of (0.16, 0.09). The hole transport characteristics of MADN are further clarified by constructing hole-only device and performing impedance spectroscopy analysis. The results indicate that MADN shows superior hole-transport ability which is almost comparable to typical hole-transport material of N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-benzidine (NPB), suggesting a promising application for constructing efficient blue OLED with integrated hole-transport layer and emitting layer. 相似文献
Highly efficient near-infrared (NIR) emitters have significant applications in medical and optoelectronic fields, but the development stays a great challenge due to the energy gap law. Here, we report two NIR phosphorescent Ir(III) complexes which display emission peaks around 730 nm with a narrow full width at half maximum of only 43 nm. Therefore, pure NIR luminescence can be obtained without having a very long emission wavelength, thus alleviating the restriction of the energy gap law, and obtaining impressively high photoluminescence quantum yield up to 0.70. More importantly, the pure NIR organic light-emitting diode (OLED) fabricated by the solution-processed mothed shows outstanding device performance with the highest external quantum efficiency of 16.43 %, which sets a new record for solution-processed NIR-OLEDs based on different emitters. This work sheds light on the development of Ir(III) complexes with narrowband emissions as highly efficient pure NIR-emitters. 相似文献
Summary: An O‐hexyl‐3,5‐bis(terpyridine)phenol ligand has been synthesized and transformed into a hexagonal Zn(II)‐metallomacrocycle by a facile self‐assembly procedure capitalizing on terpyridine‐Zn(II)‐terpyridine connectivity. The structural composition was confirmed by NMR and mass spectral techniques; photo‐ and electroluminescence properties were also investigated. The OLED device shows green electroluminescent emission at 515 nm with a maximum luminance of 39 cd · m−2 and maximum efficiency of 0.16 cd · A−1.
Structure and electroluminescent properties of the metallomacrocycle investigated. 相似文献
N-type hosts for long lifetime in sky-blue thermally-activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs) were investigated by synthesizing four hosts with zig-zag-type backbone structure for high triplet energy. The four hosts had two CN units at different positions of the zig-zag-type backbone structure and two dibenzofuran units through either the 2 or 4-position of dibenzofuran. The position of the CN unit was controlled at the meta and para-positions in the zig-zag-type backbone to study the relationship between material parameters and lifetime of the TADF OLEDs. It was revealed that the meta-orientation of the CN units in the backbone was advantageous to extend device lifetime of the sky-blue TADF OLEDs. 相似文献
Functionalization of a red phosphorescent iridium(III) complex core surrounded by rigid polyphenylene dendrons with a hole‐transporting triphenylamine surface allows to prevent the intermolecular aggregation‐induced emission quenching, improves charge recombination, and therefore enhances photo‐ and electroluminescence efficiencies of dendrimer in solid state. These multifunctional shape‐persistent dendrimers provide a new pathway to design highly efficient solution processable materials for phosphorescent organic light‐emitting diodes (PhOLEDs). 相似文献