RESUMEN
We show that sensitized superbroadband near-IR (NIR) emission in bismuth glass/Si nanocrystal superlattices can be realized. Photoluminescence is enhanced by 1 order of magnitude in this structure. We observed that the excitation wavelength dependence of the NIR emission does not show any distinct structure corresponding to the direct transition of bismuth IR-active centers. Our results suggest that the enhanced emission might result from the energy transfer from Si nanocrystals to IR-active bismuth. This structure may find broad applications for broadband amplifiers and broadly tunable laser sources.
RESUMEN
We have shown that tunable and highly efficient broadband near-IR (NIR) luminescence can be realized in erbium/bismuth codoped zeolites. The emission covers the ranges of 930-1450nm and 1450-1630nm. The intensity ratio of the two bands can be tuned by adjusting the concentration of erbium and the excitation wavelength. Steady-state and time-resolved photoluminescence (PL), and PL excitation measurements indicate that two kinds of emitters coexist in the pores of zeolites, and that NIR active bismuth simultaneously acts as a sensitizer of erbium. The present results demonstrate an important rational strategy for the design of a tunable NIR-emitting zeolite-based nanosystem.
RESUMEN
Erbium silicate (Er2SiO5 and Er4Si3O12) nanostructures were successfully synthesized by a facile molten-salt approach in the presence of NaCI and surfactant. The synthesized products were structurally and morphologically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM), whereas the luminescent properties were characterized by temperature-dependent luminescence measurements. The results revealed that the composition, crystalline phase, and yield of the final products can be readily controlled by choosing suitable surfactant and tailoring the molar ratio of reactants used for the reactions. Moreover, the single-crystalline nature of Er2SiO5 and of Er4Si3O12 nanostructures results in sharp photoluminescence (PL) of Er3+, and both nanostructures are immunized from temperature quenching of PL. We suggest that the nanostructures developed in the present work are promising building blocks for Si-based optoelectronics nanodevices.
RESUMEN
Er(3+) and Ni(2+) doped single-crystalline Al(18)B(4)O(33) nanorods were synthesized by a facile one-step toxic-free combustion method. The products were characterized by x-ray diffraction, transmission electron microscopy, selected area electron diffraction, and integrated and time-resolved photoluminescence (PL) measurements. The phase purity, morphology, and PL properties of Er(3+) and Ni(2+) doped Al(18)B(4)O(33) nanorods can be readily controlled by tailoring the annealing temperature. The mechanism for the formation of Al(18)B(4)O(33) nanorods with different aspect ratio is discussed. Er(3+) doped Al(18)B(4)O(33) nanorods show strong PL centered at 1531 nm, while Ni(2+) doped products show superwide PL with a full width at half maximum of up to 250 nm. These aluminum borate nanostructures are promising building blocks for optoelectronics nanodevices.
RESUMEN
We have shown that efficient superbroadband near-IR luminescence can be realized in bismuth-doped high-silica nanocrystalline zeolites. The emission band covered the range of 930-1620 nm, with a maximum peak at 1146.3 nm, an FWHM of 152 nm, and a lifetime of over 300 mus under the excitation of a 488 nm laser line. The observed luminescence was attributed to subvalent Bi (Bi(+)) ions formed in the annealed zeolites. These Bi-doped nanozeolites may find applications as superbroadband near-IR nano-optical sources.
RESUMEN
Significantly enhanced superbroadband near infrared emission has been realized in bismuth/aluminum doped high-silica zeolite derived nanoparticles. The emission intensity can be easily tailored by the introduction of aluminum. The luminescence lifetime can reach up to 695 micros. The results reveal that the existence of charge imbalance environment caused by [AlOV(4/2)](-) units in host materials is requisite to the formation of infrared-active Bi(+). The finding presents a feasible route to design high-efficient bismuth activated infrared luminescent nanoparticles. These bismuth doped nanoparticles may find applications as superbroadband near infrared nano optical sources.
