Bright & blue: A strategy for reducing metal‐chelate internal strain enables the preparation of blue emitting iridium(III) carbene complexes (see picture; Ir red, N light blue, F green). The phosphorescent OLED fabricated from one of these complexes shows remarkable CIE coordinates of (0.16, 0.13) and peak efficiencies of 6.0 % photons per electron, 6.3 cd A−1, and 4.0 lm W−1.

Rational design and synthesis of Ir(III) complexes (1-3) bearing two cyclometalated ligands (C--N) and one 2-(diphenylphosphino)phenolate chelate (P--O) as well as the corresponding Ir(III) derivatives (4-6) with only one (C--N) ligand and two P--O chelates are reported, where (C--NH)=phenylpyridine (ppyH), 1-phenylisoquinoline (piqH), and 4-phenylquinazoline (nazoH). Single crystal X-ray diffraction studies of 3 reveal a distorted octahedral coordination geometry, in which two nazo ligands adopt an eclipsed configuration, with the third P--O ligand located trans to the phenyl group of both nazo ligands, confirming the general skeletal pattern for 1-3. In sharp contrast, complex 4 reveals a trans-disposition for the PPh2 groups, along with the phenolate groups residing opposite the unique cyclometalated ppy ligand, which is the representative structure for 4-6. These Ir(III) complexes exhibit green-to-red photoluminescence with moderate to high quantum efficiencies in the degassed fluid state and bright emission in the solid state. For 1-6, the resolved emission spectroscopy and relaxation dynamics are well rationalized by the computational approach. OLEDs fabricated using 12 wt. % of 3 doped in CBP and with BCP as hole blocking material, give bright electroluminescence with lambda(max)=628 nm and CIE(xy) coordinates (0.65, 0.34). The turn-on voltage is 3.2 V, while the current efficiency and the power efficiency reach 11.2 cd A(-1) and 4.5 lm W(-1) at 20 mA cm(-2). The maximum efficiency reaches 14.7 cd A(-1)and 6.8 lm W(-1) upon switching to TPBI as hole blocking material. For evaluating device lifespan, the tested device incorporating CuPc as a passivation layer, 3 doped in CTP as an emitting layer, and BAlq as hole blocking material, shows a remarkably long lifetime up to 36,000 h at an initial luminance of 500 cd m(-2).

Leuchtend blau: Eine geringe sterische Spannung des Metallchelats ermöglicht die Synthese blau emittierender Iridium(III)‐Carbenkomplexe (siehe Bild; Ir rot, N türkis, F grün). Die phosphoreszierende Leuchtdiode, die mit einem dieser Komplexe hergestellt wurde, zeigt bemerkenswerte CIE‐Koordinaten von (0.16, 0.13) und maximale Quanten‐, Strom‐ und Lichtausbeuten von 6.0 % Photonen pro Elektron, 6.3 cd A−1 bzw. 4.0 lm W−1.

Efficientfull-spectrum white polymer lightemitting diodes (WPLEDs) were fabricated using singlelayer luminescent polymer produced by onestep plasma polymerization from naphthalene (PEN) (and car bazole (PENCB)) derivatives. W P LEDs based on the plasma polymers had demonstrated effici en t pu r e wh ite ligh t electroluminescence th at cover s the full visible spectral range w i t h excellent color stability. A new monomer injection method e nables excellent structural retention and excellent device repr oducibility. Monomers of good luminescent quality and char ge transport behavior can be selected to synthesize the light-e mitting polymer without considering their individual chemical b ehaviors. It provides an opportunity of onestep reaction with molecularly smooth, pinhole free and high quality films. Fullspectrum electroluminescence (EL) emission was originated f rom molecular excitons, intermolecular excimers and electro mers. It was produced pure stable white light emission at CIE coordinates of (0.33,0.34). Excellent luminance efficiency of 9.8 cd/A and a power efficiency of 2.1 lm/W were obtained. The efficiency reported here was based on films and devices not yet optimized. This new method merits further study as it manifests great potentials for simplifying the WPLEDs proce ss to enable a new type of high efficient, low-cost, and largearea-compatible processes.