White-emitting organometallo-silica nanoparticles for sun-like light-emitting diodes†
This work discloses a radically new way to prepare white-emitting hybrid nanoparticles, whose implementation in lighting devices provides encouraging proof-of-concept performances towards alternative sunlight sources. In detail, the new synthetic approach is based on the kinetic control of the formation of organometallic dots, built via the condensation of three emitting iridium(III) complexes, which are subsequently transformed into mesoporous silica nanoparticles. Our novel hybrid systems, which are exceptionally stable under harsh irradiation and thermal stress environments, show a bright white emission with a record photoluminescence quantum yield. Their remarkable performance prompted us to implement them into single-component hybrid light-emitting diodes (HLEDs), achieving a high-quality sunlight source that is stable for >2000 hours with linearly extrapolated stabilities of >10 000 h. This represents one of the most stable HLEDs reported so far, while the versatility of our synthesis approach with respect to the type of emitters opens new opportunities for the design and fabrication of white-emitting color down-converters for HLEDs in the future.