Tunable Multicolor Phosphorescence of Crystalline Polymeric Complex Salts with Metallophilic Backbones

A total of 35 [Au(NHC)₂][MX₂] (NHC=N‐heterocyclic carbene; M=Au or Cu; X=halide, cyanide or arylacetylide) complex salts were synthesized by co‐precipitation of [Au(NHC)₂]⁺ cations and [MX₂]^? anions. These salts contain crystallographically determined polymeric Au???Au or Au???Cu interactions and are highly phosphorescent with quantum yields up to unity and emission color tunable in the entire visible regions. The nature of the emissive excited states is generally assigned to ligand (anion)‐to‐ligand (cation) charge‐transfer transitions assisted by d¹⁰???d¹⁰ metallophilicity. The emission properties can be further tuned by controlled triple‐component co‐crystallization or by epitaxial growth. Correct recipes for white light‐emitting phosphors with quantum yields higher than 70 % have been achieved by screening the combinatorial pool.     

High refractive index adamantane‐based silicone resins for the encapsulation of light‐emitting diodes

The encapsulation of high power light emitting diode (LED) needs the silicone resins to have relative high refractive index and thermal‐aging properties. Herein, high refractive index adamantane‐based phenyl epoxy‐silicone (APES) resins for LED encapsulation were synthesized by the sol‐gel condensation of 1‐adamantane methanol propyltrimethoxysilane‐3‐urethane, γ‐(2,3‐epoxypropoxy)propytrimethoxysilane and diphenylsilanediol. These adamantane‐based silicone resins have multifunctional groups including adamantyl group, phenyl group, and epoxy group in order to meet the various requirements for LED encapsulation. Importantly, the adamantane group in the silicone resins benefits for high refractive index and anti‐thermal properties. These APES resins were characterized by proton nuclear magnetic resonance and Fourier transform infrared spectroscopy. When APES resins were cured by methylhexahydrophthalic anhydride, they showed relatively high refractive index of 1.56, high hardness, and high thermal resistance. The encapsulated LED demonstrated high adhesion properties by red‐ink tests. These merits make adamantane‐based silicone resins promising candidates as LED encapsulation materials.     

High-efficiency,solution-processable,multilayer triple cation perovskite light-emitting diodes with copper sulfide–gallium–tin oxide hole transport layer and aluminum-zinc oxide–doped cesium electron injection layer

Light-emitting diodes with perovskite luminophores have great potential in next-generation displays because of their exceptional color purity with narrow emission bandwidth, broadband color tunability, and solution processability. However, their low luminescent efficiency is a critical drawback. Here, we report the first demonstration of a multicolor, large-area, perovskite display, which can be made flexible by using an optimized perovskite emissive layer sandwiched between inorganic metal oxide charge transport layers, all of which are coated via a facile solution process. We show that advanced interfacial engineering, especially the energy level alignment at the interface, plays a vital role in determining the device performance because of its effects on charge injection, transport, and recombination. These devices exhibit maximum current and power efficiencies of 74.25 cd A^?1 and 89.72 lm/w for green emission, 21.40 cd A^?1 and 25.84 lm/w for red emission, and 15.21 cd A^?1 and 15.84 lm/w for blue emission, respectively. Furthermore, with the introduction of inorganic charge transport layers, these devices exhibit high environmental stability, and the encapsulated devices have operating lifetimes exceeding 450 h with an initial brightness of 1000 cd/m².     

Electrochemical preparation of poly(<Emphasis Type="Italic">p</Emphasis>-phenylene) thin films

We report the electrochemical preparation of poly(p-phenylene) (PPP) thin films with a polymerization degree of approximately 20 using biphenyl as starting material. The PPP films are prepared directly on a tin oxide electrode, presenting a positive charge carrier mobility of 5×10⁻⁷ cm² V⁻¹ s⁻¹.     

Distyryl-boradiazaindacenes: facile synthesis of novel near IR emitting fluorophores

Boradiazaindacenes with methyl substituents at 3 and 5 positions were for the first time shown to undergo efficient double condensation reactions with an aromatic aldehyde yielding a series of extended conjugation dyes. These new fluorophores have absorption maxima in the range of 650-660 nm. The dyes reported here have large quantum yields with 20 nm Stokes' shifted emission peaks. The straightforward synthesis of such red shifted BODIPY derivatives is important in relation to the synthesis of novel and useful fluorescent chemosensors. In addition, this facile transformation may make these new fluorophores' building blocks in the construction of large functional supramolecular systems.     

Synthesis,characterization, and electroluminescence of new conjugated PPV derivatives bearing triphenylamine side‐chain through a vinylene bridge

Three new conjugated poly(p‐phenylene vinylene) (PPV) derivatives bearing triphenylamine side‐chain through a vinylene bridge, poly(2‐(4′‐(diphenylamino)phenylenevinyl)‐1,4‐phenylene‐vinylene) (DP‐PPV), poly(2‐(3′‐(3″,7″‐dimethyloctyloxy)phenyl)‐1,4‐phenylenevinylene‐alt‐2‐(4′‐ (diphenylamino)phenylenevinyl)‐1,4‐phenylenevinylene) (DODP‐PPV), and poly(2‐(4′‐(diphenylamino)phenylenevinyl)‐1,4‐phenylenevinylene‐co‐2‐(3′,5′‐bis(3″,7″‐dimethyloctyloxy)‐1,4‐phenylenevinylene) (DP‐co‐BD‐PPV), were synthesized according to the Gilch or Wittig method. Among the three polymers, the copolymer DP‐co‐BD‐PPV is soluble in common solvents with good thermal stability with 5% weight loss at temperatures higher than 386°C. The weight‐average molecular weight (M_w) and polydispersity index (PDI) of DP‐co‐BD‐PPV were 1.83 × 10⁵ and 2.33, respectively. The single‐layer polymer light‐emitting diodes (PLEDs) with the configuration of Indium tin oxide (ITO)/poly (3,4‐ethylenedioxythiophene): poly(4‐styrene sulfonate)(PEDOT:PSS)/DP‐co‐BD‐PPV/Ca/Al were fabricated. The PLED emitted yellow‐green light with the turn‐on voltage of ca. 4.9 V, the maximum luminance of ca. 990 cd/m² at 15.8 V, and the maximum electroluminescence (EL) efficiency of 0.22 cd/A. Copyright © 2007 John Wiley & Sons, Ltd.     

与聚合物发光器相关的若干问题的研究

结合作者在聚合物发光器相关的若干问题的研究结果，评述新型可溶性导电高聚物、透明导电离聚物薄膜，多孔硅与导电离聚物异质结的研究进展。     

带烷氧基的苯基蒎烯吡啶铱配合物的合成及光物理性质

合成了一组新型的带有烷氧基团的铱(Ⅲ)配合物[Ir(RO-pppy)3], 并进行了结构表征. 该组配合物在~496 nm处有较强的三重态发射, 磷光量子产率为0.4~0.6, 三重态寿命为2~4 μs. 结果表明, 连接了长链的配合物可减少分子间的聚集, 可以用作有机电致发光器件中的磷光材料.     

Liquid‐crystalline and light‐emitting polyacetylenes

Rigid polymer backbones have often been considered to be detrimental to the packing of mesogenic pendants, and polyacetylenes have generally been regarded as unpromising materials for light‐emitting applications. Our group, however, has succeeded in creating a series of liquid‐crystalline polyacetylenes with rigid backbones and a variety of light‐emitting polyacetylenes with luminescent chromophores. Here we demonstrate that the rigid polyacetylene skeleton can play a constructive role in guiding the alignments of mesogenic pendants and prove that polyacetylenes can be highly emissive with photoluminescence quantum yields of up to 98% and electroluminescence performances comparable or superior to those of the best blue‐light‐emitting polymers. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2607–2629, 2003     

Synthesis and characterization of luminescent copolymers containing iminodibenzyl and divinylbenzene chromophores

New conjugated copolymers containing alternating N‐hexyl‐3,8‐iminodibenzyl and divinylbenzene chromophores {poly(N‐hexyl‐3,8‐iminodibenzyl‐1,2‐ethenylene‐2,5‐dihexyloxy‐1,4‐phenylene‐1,2‐ethenylene) ( P1 ) and poly[N‐hexyl‐3,8‐iminodibenzyl‐2,5‐bis(hexyloxy)cyanoterephthalidene] ( P2 )} were synthesized according to Wittig and Knoevenagel polymerization. A copolymer containing alternating carbazole and divinylbenzene derivatives {poly[9‐(2‐ethylhexyl)‐3,6‐carbazole‐1,2‐ethenylene‐2,5‐dihexyloxy‐1,4‐phenylene‐1,2‐ethenylene] ( P3 )} was also synthesized for comparison. The copolymers were soluble in common organic solvents such as tetrahydrofuran and toluene. Absorption and photoluminescence measurements revealed that cyano substitution at the vinylene moiety in P2 brought about a significant bathochromic shift and led to an electroluminescence color change from green to orange. The band edge energies of the copolymers were estimated from cyclic voltammograms and optical band gaps. P1 and P3 showed similar highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels, indicating that the electron‐donating abilities of the iminodibenzyl and carbazole chromophores were comparable. However, compared with those of P1 and P3 , the HOMO and LUMO levels of P2 were greatly reduced because of conjugating and electron‐withdrawing CN groups. The threshold electric field of an Al/ P1 /ITO glass single‐layer light‐emitting diode was approximately 10 × 10⁵ V/cm, whereas those for P2 and P3 were 7.5 and 16 × 10⁵ V/cm, respectively. The electroluminescence emission maxima of P1–P3 were 498, 514, and 559 nm, respectively. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3847–3857, 2002