We synthesized reddish-orange luminescent La_(10)W_(22)O_(81)(LWO):Sm^(3+)microphosphors by hydrothermalassisted solid-state reaction.X-ray diffraction analysis reveals that all the studied phosphors crystallize in an...We synthesized reddish-orange luminescent La_(10)W_(22)O_(81)(LWO):Sm^(3+)microphosphors by hydrothermalassisted solid-state reaction.X-ray diffraction analysis reveals that all the studied phosphors crystallize in an orthorhombic structure in the Pbcn space group(60),Field emission scanning electron microscopy indicates that the LWO:1.5 mol% Sm^(3+)phosphor displays a smooth-surfaced hexagonal rod-like shape,with a closed shape at both ends,and high-resolution transmission electron microscopy demonstrates a robust crystalline structure.The chemical composition and valence states of the phosphor were investigated using X-ray photoelectron spectroscopy.At 403 nm excitation,LWO:1.5 mol% Sm3+exhibits maximum intensity with the strongest band at 596 nm(^(4)G_(5/2)→^(6)H_(7/2)) in the reddish-orange region.The intensity of Sm^(3+) emission decreases beyond 1.5 mol% owing to concentration quenching regulated by dipole-quadrupole interaction between Sm^(3+)ions.The optimized microphosphor LWO:1.5 mol% Sm^(3+)exhibits color coordinates(0.5760,0.4207),which is close to that of the Amber LED-NSPAR 70 BS(0.570,0.420),displaying the highest color purity of 99.2% and correlated color temperature of 1694 K.In addition,both breast cancer cells MCF-7 and normal lung fibroblasts WI-38 were tested for toxicity with the optimized microphosphor.It is found that the LWO:1.5 Sm^(3+)microphosphor is extremely toxic to cancer cells,but not to normal cells.Based on these results,LWO:Sm^(3+)microphosphor can serve as a biomedical candidate for the treatment of cancer,as well as a potential multicolor emitting material for w-LEDs.展开更多
Laser direct-writing enables micro and nanoscale patterning,and is thus widely used for cutting-edge research and industrial applications.Various nanolithography methods,such as near-field,plasmonic,and scanning-probe...Laser direct-writing enables micro and nanoscale patterning,and is thus widely used for cutting-edge research and industrial applications.Various nanolithography methods,such as near-field,plasmonic,and scanning-probe lithography,are gaining increasing attention because they enable fabrication of high-resolution nanopatterns that are much smaller than the wavelength of light.However,conventional methods are limited by low throughput and scalability,and tend to use electron beams or focused-ion beams to create nanostructures.In this study,we developed a procedure for massively parallel direct writing of nanoapertures using a multi-optical probe system and superresolution near-fields.A glass micro-Fresnel zone plate array,which is an ultra-precision far-field optical system,was designed and fabricated as the multi-optical probe system.As a chalcogenide phase-change material(PCM),multiple layers of Sb_(65)Se_(35) were used to generate the super-resolution near-field effect.A nanoaperture was fabricated through direct laser writing on a large-area(200×200mm^(2))multi-layered PCM.A photoresist nanopattern was fabricated on an 8-inch wafer via near-field nanolithography using the developed nanoaperture and an i-line commercial exposure system.Unlike other methods,this technique allows high-throughput large-area nanolithography and overcomes the gap-control issue between the probe array and the patterning surface.展开更多
基金Project supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2021R1A6A1A03039493) by the Ministry of Science,Information and Communications Technology (ICT) and Future Planning (2022R1A2C1009389)。
文摘We synthesized reddish-orange luminescent La_(10)W_(22)O_(81)(LWO):Sm^(3+)microphosphors by hydrothermalassisted solid-state reaction.X-ray diffraction analysis reveals that all the studied phosphors crystallize in an orthorhombic structure in the Pbcn space group(60),Field emission scanning electron microscopy indicates that the LWO:1.5 mol% Sm^(3+)phosphor displays a smooth-surfaced hexagonal rod-like shape,with a closed shape at both ends,and high-resolution transmission electron microscopy demonstrates a robust crystalline structure.The chemical composition and valence states of the phosphor were investigated using X-ray photoelectron spectroscopy.At 403 nm excitation,LWO:1.5 mol% Sm3+exhibits maximum intensity with the strongest band at 596 nm(^(4)G_(5/2)→^(6)H_(7/2)) in the reddish-orange region.The intensity of Sm^(3+) emission decreases beyond 1.5 mol% owing to concentration quenching regulated by dipole-quadrupole interaction between Sm^(3+)ions.The optimized microphosphor LWO:1.5 mol% Sm^(3+)exhibits color coordinates(0.5760,0.4207),which is close to that of the Amber LED-NSPAR 70 BS(0.570,0.420),displaying the highest color purity of 99.2% and correlated color temperature of 1694 K.In addition,both breast cancer cells MCF-7 and normal lung fibroblasts WI-38 were tested for toxicity with the optimized microphosphor.It is found that the LWO:1.5 Sm^(3+)microphosphor is extremely toxic to cancer cells,but not to normal cells.Based on these results,LWO:Sm^(3+)microphosphor can serve as a biomedical candidate for the treatment of cancer,as well as a potential multicolor emitting material for w-LEDs.
基金supported by the National Research Foundation of Korea(NRF)(2015R1A5A1037668).
文摘Laser direct-writing enables micro and nanoscale patterning,and is thus widely used for cutting-edge research and industrial applications.Various nanolithography methods,such as near-field,plasmonic,and scanning-probe lithography,are gaining increasing attention because they enable fabrication of high-resolution nanopatterns that are much smaller than the wavelength of light.However,conventional methods are limited by low throughput and scalability,and tend to use electron beams or focused-ion beams to create nanostructures.In this study,we developed a procedure for massively parallel direct writing of nanoapertures using a multi-optical probe system and superresolution near-fields.A glass micro-Fresnel zone plate array,which is an ultra-precision far-field optical system,was designed and fabricated as the multi-optical probe system.As a chalcogenide phase-change material(PCM),multiple layers of Sb_(65)Se_(35) were used to generate the super-resolution near-field effect.A nanoaperture was fabricated through direct laser writing on a large-area(200×200mm^(2))multi-layered PCM.A photoresist nanopattern was fabricated on an 8-inch wafer via near-field nanolithography using the developed nanoaperture and an i-line commercial exposure system.Unlike other methods,this technique allows high-throughput large-area nanolithography and overcomes the gap-control issue between the probe array and the patterning surface.