Porphyrin Materials for Organic Light Emitting Diodes: A Route to Phosphorescent EmissionOrganic light-emitting diode technology is evolving rapidly with commercial applications in recent years. OLED materials and design are moving into an advanced stage with optimising techniques becoming more important. This work presents the use of porphyrin materials for organic electronics, specifically for organic light-emitting diodes using phosphorescent emission. The porphyrins show interesting photophysical properties which allow for an exploitation of the normally forbidden triplet energy states to achieve a significant enhancement in the device efficiency. This research presents a simple host–guest system where this concept is demonstrated. Various porphyrin structures are synthesised and tuned for OLED performance; from this, we can learn how chemical structure relates to the exciton dynamics and their resulting light emission. It is hoped that this work outlines a possible route to phosphorescent OLED technologies. |
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active layer aggregation anode applications biomolecules blend bonds Bromide Carb-Zn-Carb carbazole carbazole group carbazole porphyrins carbon Cathode charge carriers charge transport Chem chemical structure conduction conjugated current density di-carbazoles dimers displays dopant electric field electroluminescence emitting layer emitting polymers energy transfer evaporation excimer excitation exciton Fluorescence free base green emission hemin injected interface intersystem crossing layer thickness lifetimes light emitting diodes luminescence MEH–PPV metallated porphyrin metalloporphyrins molecular ohmic OLED devices optical properties optimised orbitals organic compounds organic electronics organic light emitting organic semiconductors palladium Pd-TMS Pd-TMS porphyrin Pd–TMS PFO emission Phenyl PhOLED PhOLED device phosphorescent phosphorescent OLED Photoluminescence photons Phys pixels PL emission plot porphyrin porphyrin dimers porphyrin materials profilometer Q-bands quantum efficiency quenching seen in figure semiconductor shows side groups singlet solution Soret Soret band spectrum spin coated substrates Tajima thin film Tolyl traps Trimethylsilylethyl triplet turn-on voltage UV-Vis UV–Vis Wavelength nm