Highly efficient electroluminescent PtII ppy-type complexes with monodentate ligands.

Functional PtII ppy-type complexes (ppy = 2-phenylpyridine anion) with pyridine and chloride monodentate ligands are prepared, which show high electroluminescence efficiencies.

Bis-ZnII salphen complexes bearing pyridyl functionalized ligands for efficient organic light-emitting diodes (OLEDs).

Inspired by the emissive features of ZnII complexes based on bis-Schiff base ligands, bis-ZnII salphen complexes bearing pyridyl functionalized ligands have been successfully synthesized. Their photophysical features, electrochemical behavior and electroluminescent (EL) properties have been investigated in detail. The functionalized bis-ZnII salphen complexes can exhibit high thermal stability up to 417 °C, and their photoluminescence (PL) spectra show a maximal emission wavelength peak at ca. 565 nm both in solution and PMMA doped films. The PL investigation of the neat films for these functionalized bis-ZnII salphen complexes indicated that the pyridyl functionalized ligands can effectively reduce the degree of molecular aggregation to enhance their emission intensity. Taking advantage of the charge carrier injection/transporting ability of the pyridyl functionalized ligands and their dendritic design, the optimized EL devices fabricated by a simple solution-processing method can achieve a peak luminance (Lmax) of 3589 cd m-2, a maximal external quantum efficiency (ηext) of 1.46%, a maximal current efficiency (ηL) of 4.1 cd A-1 and a maximal power efficiency (ηp) of 3.8 lm W-1. These results should afford important instructions for exploiting high performance fluorescent emitters based on dinuclear ZnII complexes.

High Triplet Energy Level Achieved by Tuning the Arrangement of Building Blocks in Phosphorescent Polymer Backbones for Furnishing High Electroluminescent Performances in Both Blue and White Organic Light-Emitting Devices.

A high triplet energy level (ET) of ca. 2.83 eV has been achieved in a novel polymer backbone through tuning the arrangement of two kinds of building blocks, showing enhanced hole injection/transporting capacity. Based on this new polymer backbone with high ET, both blue and white phosphorescent polymers were successfully developed with a trade-off between high ET and enhanced charge-carrier transporting ability. In addition, their photophysical features, electrochemical behaviors, and electroluminescent (EL) properties have been characterized in detail. Benefitting from the advantages associated with the novel polymer backbone, the blue phosphorescent polymers show top-ranking EL performances with a maximum luminance efficiency (ηL) of 15.22 cd A-1, corresponding to a power efficiency (ηP) of 12.64 lm W-1, and external quantum efficiency (ηext) of 6.22% and the stable Commission Internationale de L'Eclairage (CIE) coordinates of (0.19, 0.38). Furthermore, blue-orange (B-O) complementary-colored white phosphorescent polymers based on this novel polymer backbone were also obtained showing encouraging EL efficiencies of 12.34 cd A-1, 9.59 lm W-1, and 4.10% in the optimized WOLED together with exceptionally stable CIE coordinates of (Δx = 0.014, Δy = 0.010) in a wide driving voltage range from 4 to 16 V. All of these attractive EL results achieved by these novel phosphorescent polymers show the great potential of this new polymer backbone in developing highly efficient phosphorescent polymers.