A new family of anthracene core, highly fluorescent emitters is synthesized which include diphenylamine hole transport end groups. Using a very simple one or two layer organic light emitting diode (OLED) structure, devices without outcoupling achieve an external quantum efficiency of 6% and photonic efficiencies of 20 cd/A. The theoretical maximum efficiency of such devices should not exceed 3.55%. Detailed photophysical characterization shows that for these anthracene based emitters 2T1≤Tn and so in this special case, triplet fusion can achieve a singlet production yield of 0.5. Indeed, delayed electroluminescence measurements show that triplet fusion contributes 59% of all singlets produced in these devices. This demonstrates that when triplet fusion becomes very efficient, fluorescent OLEDs even with very simple structures can approach an internal singlet production yield close to the theoretical absolute maximum of 62.5% and rival phosphorescent‐based OLEDs with the added advantage of much improved stability.

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We report a simple yet highly efficient route to prepare polymers with a variety of pendant iridium complexes as potential materials in organic light-emitting diodes by employing click chemistry.

Solution-processable copolymers with pendant phosphorescent iridium complexes and 2,7-di(carbazol-9-yl)fluorene-type host moieties were synthesized using ruthenium-catalyzed ring-opening metathesis polymerization. Low polydispersity indices and molecular weights around 20 000 Da were obtained for all copolymers. As a result of the living character of the polymerization of the monomer containing the host moiety, a high degree of control over the molecular weights of all copolymers can be obtained. The photo-and electroluminescence properties of the copolymers were investigated. All copolymers retained the photo-and electrophysical properties of the corresponding nonpolymeric iridium complexes. Furthermore, as a proof of principle for the potential use of these materials, organic light-emitting devices were fabricated using the orange-emitting copolymer. A maximum external quantum efficiency of 1.9% at 100 cd/m 2 and a turn-on voltage of 3.7 V were obtained with photoluminescence quantum yield of 0.10 demonstrating the potential of these copolymers as emissive materials for display and lighting applications.

A norbornene-functionalized derivative of acetylacetone has been used to synthesize a series of new polymerizable norbornene-derivatized phosphorescent platinum complexes of the form Pt(C∧N)(O∧O*) where C∧N represents a cyclometalated ligand and O∧O* represents the functionalized acetylacetonate ligand. The complexes have been fully characterized, and the structures of three examples have been determined by X-ray diffraction. Solution absorption and luminescence spectra and electrochemical data are very similar to those for analogues without these polymerizable groups. A 9,9-dialkyl-2,7-di(carbazol-9-yl)fluorene material, in which one of the alkyl groups bears a norbornene group, has been synthesized and copolymerized with the Pt(C∧N)(O∧O*) complexes using Grubbs ruthenium catalysts, resulting in copolymers with broad molecular weight distributions. The copolymers have been used as lumophores in organic light-emitting diodes, thus demonstrating that platinum phosphors can be successfully integrated into the “hybrid” approach to organic light-emitting diodes, in which molecules with transport or luminescent properties are covalently attached to electronically inert polymer backbones to give solution-processible materials. Emission from aggregate states appears to play a similar role in these copolymers to that seen in vapor-deposited devices based on small phosphor and host molecules; in particular, considerable aggregate emission is observed when a phosphor with blue solution emission is used in the devices.

Orange‐emitting phosphorescent copolymers containing iridium complexes and bis(carbazolyl)fluorene groups in their side chains are employed as the emissive layer in multilayer organic light‐emitting diodes (OLEDs). The efficiency of the OLED devices is optimized by varying characteristics of the copolymers: the molecular weight, the iridium loading level, and the nature and length of the linker between the side chains and the polymer backbone. A maximum efficiency of 4.9 ± 0.4%, 8.8 ± 0.7 cd A−1 at 100 cd m−2 is achieved with an optimized copolymer.

Poly(cyclooctene)s with pendant Alq3 and fac‐Ir(ppy)3 were synthesized. Carbazole‐based comonomers were used to increase the solubility of the polymers and to transfer the energy into metal complexes. Excitation spectra of all polymers provided evidence of energy transfer. We established that the polymer backbone does not interfere with the optical properties of the metal complexes. All copolymers retained the optical properties of their small molecule metal complex analogs in solution and the solid state, making these polymers promising materials for potential electro‐optical applications.

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