Efficient OLED devices have been fabricated using organometallic complexes of platinum group metals. Still, the high material cost and low stability represent central challenges for their application in commercial display technologies. Based on its innate stability, gold(III) complexes are emerging as promising candidates for high-performance OLEDs. Here, a series of alkynyl-, N-heterocyclic carbene (NHC)- and aryl-gold(III) complexes stabilized by a κ3-(N^C^C) template have been prepared and their photophysical properties have been characterized in detail. These compounds exhibit good photoluminescence quantum efficiency (ηPL) of up to 33 %. The PL emission can be tuned from sky-blue to yellowish green colors by variations on both the ancillary ligands as well as on the pincer template. Further, solution-processable OLED devices based on some of these complexes display remarkable emissive properties (ηCE 46.6 cd.A−1 and ηext 14.0 %), thus showcasing the potential of these motifs for the low-cost fabrication of display and illumination technologies. 相似文献
A series of novel red phosphorescent polymers is successfully developed through Suzuki cross‐coupling among ambipolar units, functionalized IrIII phosphorescent blocks, and fluorene‐based silane moieties. The photophysical and electrochemical investigations indicate not only highly efficient energy‐transfer from the organic segments to the phosphorescent units in the polymer backbone but also the ambipolar character of the copolymers. Benefiting from all these merits, the phosphorescent polymers can furnish organic light‐emitting diodes (OLEDs) with exceptional high electroluminescent (EL) efficiencies with a current efficiency (ηL) of 8.31 cd A−1, external quantum efficiency (ηext) of 16.07%, and power efficiency (ηP) of 2.95 lm W−1, representing the state‐of‐the‐art electroluminescent performances ever achieved by red phosphorescent polymers. This work here might represent a new pathway to design and synthesize highly efficient phosphorescent polymers.
Electroluminescent (EL) properties of Ir(III) complex, [(2,4-diphenylquinoli-ne)]2Iridium picolinic acid N-oxide [(DPQ)2Ir(pic-N-O)] were investigated using PEDOT:PSS and reduced graphene oxide (rGO) as a hole transport layer for solution processable phosphorescent organic light-emitting diodes (PhOLEDs). High performance solution-processable PhOLED with PEDOT:PSS and (DPQ)2Ir(pic-N-O) (8 wt%) doped CBP:TPD:PBD (8:56:12) host emission layer were fabricated to give a high luminance efficiency (LE) of 26.9 cd/A, equivelent to an external quantum efficiency (EQE) of 14.2%. The corresponding PhOLED with rGO as a hole transport layer exhibited the maximum brightness and LE of 13540 cd/m2 and 16.8 cd/A, respectively. The utilization of the solution processable rGO thin films as the hole transport layer offered the great potential to the fabrication of solution processable PhOLEDs. 相似文献
The preparation of the first soluble quaterrylene derivative featuring peripheral tert‐butyl substituents and sterically hindering, core‐anchored triflate groups has been achieved. This involves a facile synthetic route based on an oxidative coupling of perylene precursors in the presence of H2O2 as oxidant. The steric hindrance between the TfO substituents at the central bay position of the quaterrylene board triggers a strong deformation of the central perylene planarity, which forces the quaterrylene platform to adopt a twisted geometry as shown by X‐ray analysis. Exceptionally, photophysical investigations show that the core‐twisted quaterrylene phosphoresces in the NIR spectral region at 1716 nm. Moreover, third‐order nonlinear optical measurements on solutions and thin film containing the relevant molecule showed very large second hyperpolarizability values, as predicted by theoretical calculations at the CAM ‐B3LYP /6‐31G** level of theory, making this material very appealing for photonic applications. 相似文献
A diversity‐oriented synthetic strategy allowed us to design a series of conjugated molecules containing multiple benzosilole units that can be utilized as efficient hole‐blocking materials for phosphorescent organic light emitting diodes (OLEDs). Some of these compounds showed a performance surpassing that of the current standard, bathocuproine. The new compounds were easily synthesized in a modular fashion from a previously reported 3‐stannyl benzosilole building unit. Studies on the properties of these compounds in solution and in the solid state indicate that they possess high electron affinity, high ionization potential, and form stable amorphous films that show high electron‐drift mobility. The correlation between their molecular properties and the efficiency of the OLED device performance is also investigated. 相似文献
High efficiency single layer blue phosphorescent organic light-emitting diodes (PHOLEDs) without any charge transport layer were developed. A mixed host of spirobifluorene based phosphine oxide (SPPO13) and 1, 1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC) was used as the host in the emitting layer. A high maximum external quantum efficiency of 15.8% and a quantum efficiency of 8.6% at 1000 cd/m2 were achieved in the single-layer blue PHOLEDs without any charge transport layer. The maximum power efficiency and power efficiency at 1000 cd/m2 were 31.4 and 16.9 lm/W, respectively. 相似文献
To take advantage of the luminescent properties of d6 transition metal complexes to label proteins, versatile bifunctional ligands were prepared. Ligands that contain a 1,2,3‐triazole heterocycle were synthesised using CuI catalysed azide–alkyne cycloaddition “click” chemistry and were used to form phosphorescent IrIII and RuII complexes. Their emission properties were readily tuned, by changing either the metal ion or the co‐ligands. The complexes were tethered to the metalloprotein transferrin using several conjugation strategies. The IrIII/RuII–protein conjugates could be visualised in cancer cells using live cell imaging for extended periods without significant photobleaching. These versatile phosphorescent protein‐labelling agents could be widely applied to other proteins and biomolecules and are useful alternatives to conventional organic fluorophores for several applications. 相似文献