Surface InP quantum dots grown by gas source molecular beam epitaxy on In0.48Ga0.52P buffer layer lattice matched to GaAs substrate shows a broad-band near-infrared photoluminescence ranging from 750 to 865 nm depende...Surface InP quantum dots grown by gas source molecular beam epitaxy on In0.48Ga0.52P buffer layer lattice matched to GaAs substrate shows a broad-band near-infrared photoluminescence ranging from 750 to 865 nm dependent on their dimensions. A reversible luminescence intensity enhancement has been observed when the quantum dots were exposed to vapours of different chemical solvents with the highest sensitivity for alcohol (methanol and ethanol) vapours. The luminescent behaviour is dependent on the solvent type and concentration. The peak energy and band shape of the luminescence are not affected by the solvent vapour.展开更多
We report the synthesis and photophysical characterization of four 9,10-disubstituted dipheny-lanthracenes with specific modifications of the model backbone which involve both the 9,10 para substituents at the phenyl ...We report the synthesis and photophysical characterization of four 9,10-disubstituted dipheny-lanthracenes with specific modifications of the model backbone which involve both the 9,10 para substituents at the phenyl rings and the substitution with carbon-carbon triple bonds. The effects of such modifications on the photoluminescence and electroluminescence properties have been investigated on the basis of the diphenylanthracene molecular characteristics and in view of application to light-emitting devices. We have found that the substitution with the carbon-carbon triple bonds at the two 9,10-phenyls noticeably alters the electronic states of the reference molecule, also introducing a certain degree of sensitivity to the phenyl substituents, which improves the tunability of the optical emission. Differently, the 9,10 para substituents produce minor changes in the single-molecule properties, due to the lack of electronic conjugation across the 9,10-phenyls. However, even a single nitro substituent in the phenyl para position produces the formation of excimers, which appreciably reduces the optical quantum efficiency. These properties are maintained in solid-state blends and simple spin-coated bilayer electroluminescent devices have been fabricated.展开更多
文摘Surface InP quantum dots grown by gas source molecular beam epitaxy on In0.48Ga0.52P buffer layer lattice matched to GaAs substrate shows a broad-band near-infrared photoluminescence ranging from 750 to 865 nm dependent on their dimensions. A reversible luminescence intensity enhancement has been observed when the quantum dots were exposed to vapours of different chemical solvents with the highest sensitivity for alcohol (methanol and ethanol) vapours. The luminescent behaviour is dependent on the solvent type and concentration. The peak energy and band shape of the luminescence are not affected by the solvent vapour.
文摘We report the synthesis and photophysical characterization of four 9,10-disubstituted dipheny-lanthracenes with specific modifications of the model backbone which involve both the 9,10 para substituents at the phenyl rings and the substitution with carbon-carbon triple bonds. The effects of such modifications on the photoluminescence and electroluminescence properties have been investigated on the basis of the diphenylanthracene molecular characteristics and in view of application to light-emitting devices. We have found that the substitution with the carbon-carbon triple bonds at the two 9,10-phenyls noticeably alters the electronic states of the reference molecule, also introducing a certain degree of sensitivity to the phenyl substituents, which improves the tunability of the optical emission. Differently, the 9,10 para substituents produce minor changes in the single-molecule properties, due to the lack of electronic conjugation across the 9,10-phenyls. However, even a single nitro substituent in the phenyl para position produces the formation of excimers, which appreciably reduces the optical quantum efficiency. These properties are maintained in solid-state blends and simple spin-coated bilayer electroluminescent devices have been fabricated.
