This paper reports that SiO2 is selected to fabricate broadband antireflection （AR） coatings on fused silica substrate by using glancing angle deposition and physical vapour deposition. Through accurate control of t...This paper reports that SiO2 is selected to fabricate broadband antireflection （AR） coatings on fused silica substrate by using glancing angle deposition and physical vapour deposition. Through accurate control of the graded index of the SiO2 layer, transmittance of thc graded broadband AR coating can achieve an average value of 98% across a spectral range of 300-1850 nm. Moreover, a laser-induced damage threshold measurement of the fabricated AR coating is performed by using a one-on-one protocol according to ISOl1254-1, resulting in an average damage threshold of 17.2 J/cm2.展开更多
Aqueous zinc-ion electrochromic(EC)technology,boasting the capability to fulfill both safety and cost-ef⁃fectiveness requirements,is garnering extensive attention in various application areas including smart windows,t...Aqueous zinc-ion electrochromic(EC)technology,boasting the capability to fulfill both safety and cost-ef⁃fectiveness requirements,is garnering extensive attention in various application areas including smart windows,thermal management,displays,and camouflage.However,typical inorganic EC materials,such as tungsten oxides(WO_(3)),of⁃ten suffer from slow ion diffusion kinetics and limited optical contrast within the aqueous Zn^(2+)electrolyte because of the large size and strong Coulombic interactions of the Zn^(2+),which limits their wide applicability.Here,ordered WO_(3)nanowire films,constructed by a one-step grazing angle deposition method,is demonstrated to boost the response speed and optical contrast during EC phenomena.Compared with dense films,the ordered WO_(3)nanowire films with a porosity of 44.6%demonstrate anti-reflective property and excellent comprehensive EC performance,including fast response time(3.6 s and 1.2 s for coloring and bleaching,respectively),large optical contrast(66.6%at 700 nm)and high col⁃oration efficiency(64.3 cm^(2)·C^(-1)).A large-area prototype EC device(17 cm×12 cm)with fast color-switching is also successfully achieved.Mechanistic studies show that the improved performance is mainly due to the ordered porous nanowire structures,which provides direct electron transfer paths and sufficient interfacial contacts,thus simultaneously enhancing the electrochemical activity and fast redox kinetics.This study provides a simple and effective strategy to im⁃prove the performance of tungsten oxide-based aqueous zinc ion EC materials and devices.展开更多
SnSe single crystals have been demonstrated to possess excellent thermoelectric properties.In this work,we demonstrate a grain size control method in growing nanocrystalline SnSe thin films through a glancing angle pu...SnSe single crystals have been demonstrated to possess excellent thermoelectric properties.In this work,we demonstrate a grain size control method in growing nanocrystalline SnSe thin films through a glancing angle pulsed-laser deposition approach.Structural characterization reveals that the SnSe film deposited at a normal angle has a preferred orientation along a axis,while by contrast,the SnSe film deposited at an 80glancing angle develops a nanopillar structure with the growth direction towards the incident atomic flux.The glancing angle deposition greatly reduces the grain size of the thin film due to a shadowing effect to the adatoms,resulting in significantly increased power factor for more than 100%.The maximum Seebeck coefficient and power factor are 498.5 mV=K and 18.5 mWcm^(-1)K^(-2),respectively.The enhancement of thermoelectric property can be attributed to the potential barrier scattering at grain boundaries owing to the reduced grain size and increased grain boundaries in the film.Given this enhanced power factor,and considering the fact that the nanopillar structure should have much lower thermal conductivity than a plain film,the zT value of such made SnSe film could be significantly larger than the corresponding single crystal film,making it a good candidate for thin film-based thermoelectric device.展开更多
Circular polarization selection of light is an important property of helical micro-nanostructure.The helical thin films fabricated by glancing angle deposition can provide both circular polarization selection and wave...Circular polarization selection of light is an important property of helical micro-nanostructure.The helical thin films fabricated by glancing angle deposition can provide both circular polarization selection and wavelength tuning in this work.Their selective transmissions were depicted in calculations and experiments.The wavelength tuning mechanism was revealed as the relationship between peak wavelength and deposition parameters.Therefore,tunable circular polarization components can be designed according to the mechanism mentioned above and fabricated by glancing angle deposition techniques.Potential applications include tunable optical filters,optical pulse-shapers,biosensors etc.展开更多
ZIRLO alloy specimens were implanted with carbon ions with fluence range from 1×10 16 to 1×10 18ions·cm -2, using a MEVVA source at an extraction voltage of 40 kV at maximum temperature of 380 ℃. The s...ZIRLO alloy specimens were implanted with carbon ions with fluence range from 1×10 16 to 1×10 18ions·cm -2, using a MEVVA source at an extraction voltage of 40 kV at maximum temperature of 380 ℃. The surfaces of the implanted samples were then analyzed and the TRIM 96 computer code was used to simulate the depth distribution of carbon. The valences of elements in the implanted surface of ZIRLO alloy were analyzed by X-ray photoemission spectroscopy (XPS); and then the depth distributions of the elements on the surface of the samples were obtained by Auger electron spectroscopy (AES). Scanning electron microscopy (SEM) was used to examine the micro-morphology of implanted samples. Glancing angle X-ray diffraction (GAXRD) at 0.30 incident angles was employed to examine the phase transformations of implanted samples. It shows that the as-received ZIRLO alloy is mainly composed of hexagonal alpha zirconium, as for implanted samples, there appeared hexagonal zirconia (H-ZrO_ 0.35) and sigma zirconium carbide (δ-Zr_3C_2), and the δ-Zr_3C_2 increased when increasing the fluence. When the fluence reached 1×10 18 ions·cm -2, the concentration of δ-Zr_3C_2 is the maximum in all the samples. The micro-morphology of implanted samples are similar, there are many pits with diameters ranging from 1 to 3 μm on the implanted surfaces.展开更多
Plasmonics based on localized surface plasmon resonance （LSPR） has found many exciting appli- cations recently. Those applications usually require a good morphological and structural control of metallic nanostructur...Plasmonics based on localized surface plasmon resonance （LSPR） has found many exciting appli- cations recently. Those applications usually require a good morphological and structural control of metallic nanostructures. Oblique angle deposition （OAD） has been demonstrated as a powerful technique for various plasmonic applications due to its advantages in controlling the size, shape, and composition of metallic nanostructures. In this review, we focus on the fabrication of metallic nanostructures by OAD and their applications in plasmonics. After a brief introduction to OAD technique, recent progress of applying OAD in fabricating noble metallic nanostructures for LSPR sensing, surface-enhanced Raman scattering, surface-enhanced infrared absorption, metal-enhanced fluorescence, and metamaterials, and their corresponding properties are reviewed. The future requirements for OAD plasmonics applications are also discussed.展开更多
We present a facile method for producing superhydrophobic nanograss-coated （SNGC） glass surfaces that possess both reduced reflectivity and self-cleaning properties at the air/glass interface. The refractive index o...We present a facile method for producing superhydrophobic nanograss-coated （SNGC） glass surfaces that possess both reduced reflectivity and self-cleaning properties at the air/glass interface. The refractive index of a CaF2 nanograss （NG） layer on a glass substrate, deposited by glancing angle vapor deposition, is 1.04 at 500 nm, which is the second-lowest value ever reported so far. The fluorinated NG layer gives rise to a high water contact angle （〉150°） and very efficient cleaning out of dust with water drops. Using the dual functionalities of the SNGC glass, we demonstrate superhydrophobic and antireflective organic photovoltaic cells with excellent power conversion efficiency.展开更多
Catalytic nanomotors are nano-to-micrometer-sized actuators that carry an on-board catalyst and convert local chemical fuel in solution into mechanical work. The location of this catalyst as well as the geometry of th...Catalytic nanomotors are nano-to-micrometer-sized actuators that carry an on-board catalyst and convert local chemical fuel in solution into mechanical work. The location of this catalyst as well as the geometry of the structure dictate the swimming behaviors exhibited. The nanomotors can occur naturally in organic molecules, combine natural and artificial parts to form hybrid nanomotors or be purely artificial. Fabrication techniques consist of template directed electroplating, lithography, physical vapor deposition, and other advanced growth methods. Various physical and chemical propulsion mechanisms have been proposed to explain the motion behaviors including diffusiophoresis, bubble propulsion, interracial tension gradients, and self-electrophoresis. The control and manipulation based upon external fields, catalytic alloys, and motion control through thermal modulation are discussed as well. Catalytic nanomotors represent an exciting technological challenge with the end goal being practical functional nanomachines that can perform a variety of tasks at the nanoscale.展开更多
Slanted Fe nanorods prepared by glancing angle deposition on silicon substrates exhibited easy magnetization along their growth axis. By using a thin gold film on a silicon substrate as a buffer layer, slanted Fe nano...Slanted Fe nanorods prepared by glancing angle deposition on silicon substrates exhibited easy magnetization along their growth axis. By using a thin gold film on a silicon substrate as a buffer layer, slanted Fe nanorods can be realigned towards the substrate surface normal by a strong magnetic field. After realignment, the Fe nanorods retained the easy magnetization axis along their growth axis. The effects of the realignment by the strong magnetic field on the properties of the slanted Fe nanorods were also investigated. This study provides a possible way to fabricate magnetic nanostructures for perpendicular recording applications.展开更多
Sensitive differentiation of an enantiomer from its mirror image(ie,enantiodifferentiation),a perennial challenge for pharmaceutical production and disease diagnosis,is technically limited by the weak optical activity...Sensitive differentiation of an enantiomer from its mirror image(ie,enantiodifferentiation),a perennial challenge for pharmaceutical production and disease diagnosis,is technically limited by the weak optical activity(OA)of enantiomers,mainly due to their dimensional mismatch with light wavelengths in the ultraviolet(UV)-visible region.Here we use silver chiral nanoparticles(Ag CNPs)with nominally sub-5 nm helical pitch(P)to amplify the OA of(20R,30R,40S)-riboflavin-50-phosphate sodium salts(RP),which have been found to indirectly affect metabolic processes,through the formation of an RP thin film(TF)covering a close-packed array of Ag CNPs.The OA of the RP in the deep-UV region can be amplified up to 80-fold,ascribed to the aggregation of RP in the TFs and the interactions between RP and the atomically chiral lattices at the CNPs'surfaces.The former contribution,not associated with the chiral Ag topographies,plays a dominant role by thickening the RP TFs,so that the observed amplification has no enantioselective dependence on the chirality of the Ag CNPs.This study extends progress in the sensitive detection of bio-enantiomers,which is highly desired for advanced bio-detection in disease diagnosis and production of single-enantiomer pharmaceuticals.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 10804060)Higher Educational Science and Technology Program of Shandong Province of China (Grant No. J08LI05)
文摘This paper reports that SiO2 is selected to fabricate broadband antireflection （AR） coatings on fused silica substrate by using glancing angle deposition and physical vapour deposition. Through accurate control of the graded index of the SiO2 layer, transmittance of thc graded broadband AR coating can achieve an average value of 98% across a spectral range of 300-1850 nm. Moreover, a laser-induced damage threshold measurement of the fabricated AR coating is performed by using a one-on-one protocol according to ISOl1254-1, resulting in an average damage threshold of 17.2 J/cm2.
基金Supported by Jilin Provincial Scientific and Technological Development Program(20230508109RC,20230201051GX,20220201091GX)National Natural Science Foundation of China(62035013,61275235)。
文摘Aqueous zinc-ion electrochromic(EC)technology,boasting the capability to fulfill both safety and cost-ef⁃fectiveness requirements,is garnering extensive attention in various application areas including smart windows,thermal management,displays,and camouflage.However,typical inorganic EC materials,such as tungsten oxides(WO_(3)),of⁃ten suffer from slow ion diffusion kinetics and limited optical contrast within the aqueous Zn^(2+)electrolyte because of the large size and strong Coulombic interactions of the Zn^(2+),which limits their wide applicability.Here,ordered WO_(3)nanowire films,constructed by a one-step grazing angle deposition method,is demonstrated to boost the response speed and optical contrast during EC phenomena.Compared with dense films,the ordered WO_(3)nanowire films with a porosity of 44.6%demonstrate anti-reflective property and excellent comprehensive EC performance,including fast response time(3.6 s and 1.2 s for coloring and bleaching,respectively),large optical contrast(66.6%at 700 nm)and high col⁃oration efficiency(64.3 cm^(2)·C^(-1)).A large-area prototype EC device(17 cm×12 cm)with fast color-switching is also successfully achieved.Mechanistic studies show that the improved performance is mainly due to the ordered porous nanowire structures,which provides direct electron transfer paths and sufficient interfacial contacts,thus simultaneously enhancing the electrochemical activity and fast redox kinetics.This study provides a simple and effective strategy to im⁃prove the performance of tungsten oxide-based aqueous zinc ion EC materials and devices.
基金We thank support from The Hong Kong Polytechnic University(Grant Nos.1-ZVCG,1eZVGH,4eZZDC,and DD7F).
文摘SnSe single crystals have been demonstrated to possess excellent thermoelectric properties.In this work,we demonstrate a grain size control method in growing nanocrystalline SnSe thin films through a glancing angle pulsed-laser deposition approach.Structural characterization reveals that the SnSe film deposited at a normal angle has a preferred orientation along a axis,while by contrast,the SnSe film deposited at an 80glancing angle develops a nanopillar structure with the growth direction towards the incident atomic flux.The glancing angle deposition greatly reduces the grain size of the thin film due to a shadowing effect to the adatoms,resulting in significantly increased power factor for more than 100%.The maximum Seebeck coefficient and power factor are 498.5 mV=K and 18.5 mWcm^(-1)K^(-2),respectively.The enhancement of thermoelectric property can be attributed to the potential barrier scattering at grain boundaries owing to the reduced grain size and increased grain boundaries in the film.Given this enhanced power factor,and considering the fact that the nanopillar structure should have much lower thermal conductivity than a plain film,the zT value of such made SnSe film could be significantly larger than the corresponding single crystal film,making it a good candidate for thin film-based thermoelectric device.
基金the financial support of the project from the National Natural Science Foundation of China(Grant No.60977042)the Natural Science Foundation of Guangdong Provincial(Grant No.9151027501000070)
文摘Circular polarization selection of light is an important property of helical micro-nanostructure.The helical thin films fabricated by glancing angle deposition can provide both circular polarization selection and wavelength tuning in this work.Their selective transmissions were depicted in calculations and experiments.The wavelength tuning mechanism was revealed as the relationship between peak wavelength and deposition parameters.Therefore,tunable circular polarization components can be designed according to the mechanism mentioned above and fabricated by glancing angle deposition techniques.Potential applications include tunable optical filters,optical pulse-shapers,biosensors etc.
文摘ZIRLO alloy specimens were implanted with carbon ions with fluence range from 1×10 16 to 1×10 18ions·cm -2, using a MEVVA source at an extraction voltage of 40 kV at maximum temperature of 380 ℃. The surfaces of the implanted samples were then analyzed and the TRIM 96 computer code was used to simulate the depth distribution of carbon. The valences of elements in the implanted surface of ZIRLO alloy were analyzed by X-ray photoemission spectroscopy (XPS); and then the depth distributions of the elements on the surface of the samples were obtained by Auger electron spectroscopy (AES). Scanning electron microscopy (SEM) was used to examine the micro-morphology of implanted samples. Glancing angle X-ray diffraction (GAXRD) at 0.30 incident angles was employed to examine the phase transformations of implanted samples. It shows that the as-received ZIRLO alloy is mainly composed of hexagonal alpha zirconium, as for implanted samples, there appeared hexagonal zirconia (H-ZrO_ 0.35) and sigma zirconium carbide (δ-Zr_3C_2), and the δ-Zr_3C_2 increased when increasing the fluence. When the fluence reached 1×10 18 ions·cm -2, the concentration of δ-Zr_3C_2 is the maximum in all the samples. The micro-morphology of implanted samples are similar, there are many pits with diameters ranging from 1 to 3 μm on the implanted surfaces.
文摘Plasmonics based on localized surface plasmon resonance （LSPR） has found many exciting appli- cations recently. Those applications usually require a good morphological and structural control of metallic nanostructures. Oblique angle deposition （OAD） has been demonstrated as a powerful technique for various plasmonic applications due to its advantages in controlling the size, shape, and composition of metallic nanostructures. In this review, we focus on the fabrication of metallic nanostructures by OAD and their applications in plasmonics. After a brief introduction to OAD technique, recent progress of applying OAD in fabricating noble metallic nanostructures for LSPR sensing, surface-enhanced Raman scattering, surface-enhanced infrared absorption, metal-enhanced fluorescence, and metamaterials, and their corresponding properties are reviewed. The future requirements for OAD plasmonics applications are also discussed.
文摘We present a facile method for producing superhydrophobic nanograss-coated （SNGC） glass surfaces that possess both reduced reflectivity and self-cleaning properties at the air/glass interface. The refractive index of a CaF2 nanograss （NG） layer on a glass substrate, deposited by glancing angle vapor deposition, is 1.04 at 500 nm, which is the second-lowest value ever reported so far. The fluorinated NG layer gives rise to a high water contact angle （〉150°） and very efficient cleaning out of dust with water drops. Using the dual functionalities of the SNGC glass, we demonstrate superhydrophobic and antireflective organic photovoltaic cells with excellent power conversion efficiency.
基金Acknowledgements We acknowledge the financial support from the National Science Foundation under Contract No. CMMI-0726770 and ECCS-0901141.
文摘Catalytic nanomotors are nano-to-micrometer-sized actuators that carry an on-board catalyst and convert local chemical fuel in solution into mechanical work. The location of this catalyst as well as the geometry of the structure dictate the swimming behaviors exhibited. The nanomotors can occur naturally in organic molecules, combine natural and artificial parts to form hybrid nanomotors or be purely artificial. Fabrication techniques consist of template directed electroplating, lithography, physical vapor deposition, and other advanced growth methods. Various physical and chemical propulsion mechanisms have been proposed to explain the motion behaviors including diffusiophoresis, bubble propulsion, interracial tension gradients, and self-electrophoresis. The control and manipulation based upon external fields, catalytic alloys, and motion control through thermal modulation are discussed as well. Catalytic nanomotors represent an exciting technological challenge with the end goal being practical functional nanomachines that can perform a variety of tasks at the nanoscale.
基金The authors are grateful for financial support from the National Natural Science Foundation of China(No.50931002)and the National Basic Research Program of China(973 Program,No.2007CB-936601).
文摘Slanted Fe nanorods prepared by glancing angle deposition on silicon substrates exhibited easy magnetization along their growth axis. By using a thin gold film on a silicon substrate as a buffer layer, slanted Fe nanorods can be realigned towards the substrate surface normal by a strong magnetic field. After realignment, the Fe nanorods retained the easy magnetization axis along their growth axis. The effects of the realignment by the strong magnetic field on the properties of the slanted Fe nanorods were also investigated. This study provides a possible way to fabricate magnetic nanostructures for perpendicular recording applications.
基金GRF,Grant/Award Number:12200118National Natural Science Foundation of China,Grant/Award Number:91856127SKLP,Grant/Award Number:1920_P06。
文摘Sensitive differentiation of an enantiomer from its mirror image(ie,enantiodifferentiation),a perennial challenge for pharmaceutical production and disease diagnosis,is technically limited by the weak optical activity(OA)of enantiomers,mainly due to their dimensional mismatch with light wavelengths in the ultraviolet(UV)-visible region.Here we use silver chiral nanoparticles(Ag CNPs)with nominally sub-5 nm helical pitch(P)to amplify the OA of(20R,30R,40S)-riboflavin-50-phosphate sodium salts(RP),which have been found to indirectly affect metabolic processes,through the formation of an RP thin film(TF)covering a close-packed array of Ag CNPs.The OA of the RP in the deep-UV region can be amplified up to 80-fold,ascribed to the aggregation of RP in the TFs and the interactions between RP and the atomically chiral lattices at the CNPs'surfaces.The former contribution,not associated with the chiral Ag topographies,plays a dominant role by thickening the RP TFs,so that the observed amplification has no enantioselective dependence on the chirality of the Ag CNPs.This study extends progress in the sensitive detection of bio-enantiomers,which is highly desired for advanced bio-detection in disease diagnosis and production of single-enantiomer pharmaceuticals.
