Session Index

We propose a compact imaging system with optical sectioning capability based on Moiré metalens consisting of two complementary phase metasurfaces to perform fluorescence bio-imaging applications in visible regions. The focal length can be tuned from 10 mm to 125 mm by changing mutual angles between two metasurfaces. In addition, the speckle illumination HiLo microscope is used to reduce the effect of out-of-focus light scattering. The labeled beads as well as ex vivo mice intestine tissue samples are imaged by our system. The presented design of varifocal metalens is anticipated to realize important applications in fluorescence microscopy and endoscopy.

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A facile photoreduction synthesis of Au nanostars by ethanol action is presented for the in-situ sensitive SERS detection of antibiotic residue on chicken meat. The synthesized Au nanostars with sharp tips and clean surface not only can effectively excite strong electric field by lightning rod effect but also increase the number of adsorbed target molecules by avoiding passivation of surfactant. The superior SERS performance of Au nanostars includes high sensitivity, high enhancement factor (2.03×10^9), ultra-low limit of detection (3.41×10^-11 M), superior multiplex detection ability, excellent uniformity and reproducibility (<7.54 %).

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This study reports the preparation of recyclable TiO2/Ag nanoparticles (AgNPs) substrates by using cathodic arc plasma deposition and dc magnetron sputtering technologies.The deposited,TiO2 nano-structure ensured the photocatalytic degradation of analytes.By measuring the Raman spectra of rhodamine 6G (R6G) in titrated concentrations,a limit of detection (LOD) of 10-8 M and a SERS analytical enhancement factor (AEF) of 1.01 × 109 were attained.Self-cleaning was performed via UV irradiation,and recyclability was achieved after at least five cycles of detections and degradations.The proposed TiO2/AgNPs substrates have the potential to serve as eco-friendly SERS enhancers for label-free detection of various chemical and biological substances.

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Recently, we have discovered giant photothermal nonlinearity in the scattering and absorption of crystalline silicon (c-Si) nanostructure. Here we report that under intense laser excitation, the strong thermooptical effects result in the nonlinear dependence of the Raman scattering provided by thermal reconfiguration of resonant response and governed by the Purcell effect. This is the first direct evidence of the Purcell effect contribution over intrinsic Raman emission in all-dielectric Mie resonance nanostructures.

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We numerically analyze the resonance behavior of the nanogratings-based metal-insulator-metal resonator. It is found that resonance appears when the gratings has a lower filling ratio. In addition, there is a red shift for the resonance wavelength when compared with the theoretical value. Finally, the absorption peak becomes stronger when the grating thickness is smaller.

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Spectral tuning on deep gold nanoslit arrays as plasmonic biosensors are presented with simulation based on finite-difference time-domain calculations. By modifying the slit depth, slit width, gold film thickness, and their morphologies, the corresponding transmission spectra and electric fields at resonance wavelengths are discussed based on the mode coupling effects between surface plasmon resonance and cavity resonance. The simulation results are compared with the experimental ones to relate the morphology changes under different fabrication conditions.

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Sixth-generation (6G) network is under development, and requires faster components to meet the high carrier frequencies, ranged between 0.1-3 THz. One of the critical filters in mobile communication is based on the surface acoustic wave (SAW) resonator, with a working-frequency limit about few tens of GHz. In this research, we show a simple 2D-VA heterostructure, composed of few-nm-thick antimonene on bilayer MoS2, provide the acoustic resonator structure to meet this THz-era need. Our photoacoustic spectroscopy study revealed that this 5-nanometer structure form excellent acoustic cavity, generate 106, 332, 550, 772, and 964 GHz resonant frequencies, to drive the sub-THz filters.

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We present the hybrid integration of the side-coupled photonic crystal (PhC) nanobeam (NB) laser to the SiNx waveguide. This hybrid integration realized via a novel transfer printing technique based on the shear force can exhibit displaced and rotational misalignments far below the diffraction limitation than traditional transfer printing based on visual alignment. With modifications by reduced-PhCs and tapered beam to the NB laser, this hybrid integration theoretically shows highly unidirectional coupling efficiency to the SiNx waveguide and an over 10-times laser emission unidirectional coupling to the specific waveguide output than vertical emission to the air in experiments

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In this study, the textures of cholesteric liquid crystals (CLCs) can be transformed from focal conic to planar textures by surface acoustic waves (SAWs). It is an unusual way to change the arrangement of the CLCs. Besides, the duration of SAWs and heat are investigated.

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We theoretically and numerically investigate the chiral charge and current densities of a plasmonic two-wire transmission-line (TWTL) using the quantum theory. Our results reveal the origin of polarization actuated non-reciprocity of a TWTL circulator.



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Plasmonic two-wire transmission line formed purely by monolayer graphene is numerically investigated. We performed analysis on the modal behaviors with Fermi level and operational wavelength as sweeping parameters, indicating the potential for long-range guiding of surface plasmon polaritons.

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In this work, we integrated a periodic seed layer by e-beam lithography and oblique deposition method to fabricate a stochastically-distributed oblique-flat-sheet metamaterial perfect absorber (MPA). Such design could increase its absorption bandwidth and tolerance to high angle-incidence due to the fact that various oblique flat sheets offer different resonance conditions while even a single oblique flat sheet could provide different optical paths for resonance. On the other hand, a seed layer could reduce uncertainty regarding to direct oblique deposition and provide abilities to manipulate the bandwidth of the MPA.

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We studied the pulsed laser-induced plasmonic nanobubbles and the follow-up three types of microbubbles in gold nanorod (GNR) colloidal solution. These nanobubbles are initiated at the beginning of the irradiation, then to trigger the optical breakdown of water at the focal spot of a laser beam. Subsequently, microbubbles are formed with the aid of these nanobubbles. The phenomenon indicates that the exist of GNR significantly reduces the threshold of laser energy to generate microbubbles. We used a He-Ne laser with a photodetector and an ultrasonic transducer to investigate the dynamic formations of nanobubbles and the follow-up microbubble in GNR colloids.

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Two-dimensional 1-T phase VS2 is a potential material to perform as contact electrode with its low work function, low Schottky barrier and metallic properties. Here, we successfully fabricated high quality 1-T phase VS2 with chemical vapor deposition through molten liquid process of Na3VO4 precursors on sapphire substrate via vapor-liquid-solid method. From OM images, AFM images and Raman spectra, VS2 are characterized as the monolayer thin film. Results of electrical measurement shows the VS2 is with the properties of 1-T phase, instead of 2-H phase. With this process, we can fabricate high quality 1-T phase VS2 to apply in 2D hetero-devices

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Previous reports on the generation of isotropic red color by colloidal media are based on limited settings of structural parameters and 2D calculations. In this study, we present the optical characterization for colloidal amorphous media and investigate structural coloration of 3D colloidal structures. Strategies of producing improved red color are discussed, which may facilitate the development of new strategies for generating isotropic red coloration in 3D disorder media.

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Fundamental research on controlling the iridescence of cellulose films by manipulating the alignment and helical pitch of cellulose nanocrystals (CNCs) is required to advance cellulose photonics and develop its optoelectronic applications. Aqueous suspensions of CNCs exhibit a cholesteric liquid crystal (LC) phase with structural color; however, attaining a uniformly colored film is extremely difficult. Nevertheless, we have recognized some strategies for achieving homogeneously colored films. In particular, we have carefully observed that the drying process of aqueous suspensions significantly influences the quality of iridescence of CNC films.

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We introduced a new sulfonate ligand sodium beta-styrenesulfonate (SβSS) with elongated π-conjugation onto CsPbBr3 NCs. The sulfonate ligand can decrease the surface defects of CsPbBr3 NCs and improve photoluminescence quantum yield (PLQY) from 53 to 75% compared with the pristine perovskite NCs. Moreover, the π-conjugation of the ligand enhances the charge injection and transport capability into NCs cores. The optimized green PeLED based on the SβSS-modified CsPbBr3 NCs exhibited a maximum brightness of 10965 cd m-2 and a maximum current efficiency of 10.9 cd A-1, revealing 2.5- and 2.4-fold enhancement compared with the device based on the pristine NCs.

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We synthesize perovskite quantum dots (PeQDs) having a high photoluminescence quantum yield (PLQY = 98%) for light-emitting applications. We blend the PeQDs with polyvinylcinnamate to formulate photopatternable thin films. The resulting perovskite quantum dot–polymer nanocomposites (PQD-PNCs) can be patterned using UV light to provide feature sizes as small as 3.86 μm. The highest PLQY of the PQD-PNC film (47%) is greater than that of the neat QD film (40%). The results suggest the high potential of PQD-PNCs as effective color-conversion layers for future micro-LEDs.

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Recently, all dielectric metasurface exhibits a ultranarrow band resonant spectrum, called bound states in the continuum (BIC) is frequently utilized for biosensing applications. Due to its the specific resonance, all-dielectric metasurface can be highly sensitive in the refractive index changed by the surround medium. A TiO2 nanohole metasurface excited by 650 nm light source reaches the sensitivity of 276.67 nm/RIU by COMSOL simulation is presented in this work and provide a promising way to design high sensitivity biosensors.

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The excitons of a monolayer (ML) TMDC suspended in air are decreased screen effect by from the substrate dielectric, resulting the enhancement of photon emission. .In the study, we demonstrated the lasing action of suspended ML tungsten diselenide (WSe2) on a microdisk peripherally surrounded by an air gap. In absence of substrates, the photoluminescence of suspended ML WSe2 was enhanced by five folds. With ML WSe2 on the microdisk with an air gap, the device showed a lower lasing threshold and better performance than those corresponding to a generic microdisk covered by the 2D material.

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In this study, electrochromic devices with high optical modulation were fabricated by depositing amorphous WO3 nanostructures on ITO glass using potentiostatic electrodeposition. The increase of Na2WO4·2H2O concentration promoted the deposition of WO3. However, a thicker WO3 film decreased transmittance and declined the electrochromic characteristics. An optimal optical modulation of 77.7% was obtained using 25 mM of Na2WO4·2H2O. The embedded charge was 0.02749 C/cm2, and the coloration efficiency reached 49.2 cm2/C. The coloration and bleaching times were 5.3 and 5.2 s, respectively. The electrochromic device exhibited high optical modulation and a fast switching performance.

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The power conversion efficiency of a Si-based solar cell is improved by changing the materials and the cell structures. Our research findings show that the nanorod solar cells with the n-type omega(Ω)-shaped concentration doping have better performance than those doped with full-area, where ITO is used as the top electrode and silicon dioxide is filled between the nanorod structures. Both optical and electric properties are simulated based on Lumerical software with FDTD and CHARGE solvers.

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The magnesium oxide is one of the promising candidate’s materials that can act as solar blind photodetectors. However, the intrinsically low thermal conductivity of MgO,which is restrict the application in electric device. The magnesium oxide exhibits the poor conductivity which could improved by doing method. This paper fabricated magnesium indium oxide (MgInO) solar-blind photodetectors by MgInO film was deposited on glass substrate by co-sputtering using MgO and In2O3 targets with different oxygen flow.


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Zinc oxide (ZnO) materials are widely used in gas sensing. This study performed deposition of aluminum-doped ZnO (AZO) nanofilms through radiofrequency magnetron sputtering. Oxygen flux and power during sputtering were altered to adjust the films’ surface morphology, produce a highly porous structure, and increase sensitivity to carbon monoxide. The results demonstrate that an oxygen flux of 10 sccm and sputtering power of 175 W produced films with favorable surface morphology and increased the maximum CO response value. Thus, the surface structure of the films can be adjusted by optimizing sputtering parameters, which increases sensitivity to CO gas reactions.

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The methylammonium lead bromide perovskite (MAPbBr3)-embedded nanofibers were fabricated by the uniaxial electrospinning technique. Through the differences of solidification properties and immiscibility between perovskite precursor, polymethyl methacrylate (PMMA) and Polyacrylonitrile (PAN), the perovskite nanoparticles mainly are concentrated in the core area, also, the PMMA and PAN provide a smooth surface and waterproof environment, benefiting the lasing behavior happened. Further, we observed its photoluminescence performance. The single-mode lasing action was successfully achieved from single nanofiber.

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Photo-induced negative differential resistance (NDR) accompanied with resistive switching based on glutamine-functionalized MoS2 quantum dots has been demonstrated. By increasing the illuminated light power on the Au/MoS2-quantum-dot/Au structure, the NDR effect can be enhanced significantly. The light-induced NDR originated from the tunneling transport and carrier trapping of the interface states between MoS2 quantum dots and Au. By changing the illuminated light intensity, multi-level resistive switching can be realized, which provides potential applications in multi-level memory devices.

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In this work, we propose a cost-effective strategy to construct an ultraviolet (UV) light heterostructure photodetector via spin coating FAPbI3 nanoparticles on a monolayer graphene film, which has an outstanding detection of UV light. The heterostructure photodetector exhibits a responsivity of 4.5 A/W and detectivity of 6.79×109 Jones at an incident power of 199 mW under 365 nm illumination. This high performance can be attributed to the combination of the strong light absorption of the perovskite material and the high mobility graphene, leading to a high exciton ability and photocurrent under UV light illumination.

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In this study, a NiO buffer layer was prepared to improve the electroluminescence (EL) of organic light-emitting diodes (OLEDs), where the OLED structure was ITO/NiO/NPB/Alq3/Bphen/LiF/Al. The insertion of an ultrathin NiO buffer layer enhanced the injection of holes. Consequently, carrier balance in the luminescent layer was achieved, and the OLED efficiency was improved. EL measurements showed that when a 1-nm-thick NiO was inserted, the luminous intensity and current density of the OLEDs were increased by 33.2% and 10.9%, respectively. The power efficiency increased by 27.5%, and the external quantum efficiency increased by 21.1%.

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In this study, an additive of micron-sized ceramic powder was used to enhance the mechanical properties of 3D printing resin. It was observed that adding an appropriate proportion of micron-sized ceramic powder could improve the tensile strength of the polymer resin. It is expected that the temporal bone surgery simulator printed with the synthesized composite resin would be able to solve the problem of expensive costs in surgical training.

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In this study, there are two objectives had been done. The first involved the fabrication of a white light emitting diode (LED) with a high color rendering index (CRI) through the near-ultraviolet excitation of phosphors, and the phosphor ratios were adjusted to obtain a color temperature of 2800 K. Then due to this LED had relatively low brightness, the second objective entailed the addition of gold nanoparticles at various concentrations to enhance light reflection within the LED, thereby improving the light output. A white LED with a high CRI and a high light intensity was successfully developed.

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We propose a design for a millimeter-scale 2D free-space beam emitter, which converts the subwavelength mode size of a silicon waveguide to a millimeter-scale Gaussian beam. The beam emitter consists of two stages of engineered coupling. The first stage relies on the coupling between a strip waveguide and a slab waveguide, and the second stage uses a meta-grating to couple the slab waveguide mode to the free space. The semi-analytical design is verified with the finite-difference time-domain (FDTD) simulation.

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This paper uses pulsed laser deposition to grow copper oxide films on C-surface sapphire substrates with a laser wavelength of 266 nm, a pulse width of <10 ns, and a pulse frequency of 10 Hz, and studies the effects on the growth of copper oxide films by changing the substrate temperature, deposition time, gas type, and background gas pressure. The photocatalytic properties were also studied. The photocatalytic effect was analyzed by measuring the crystal structure by X-ray diffraction spectroscopy (XRD) and the penetration spectrum by UV-VIS spectroscopy, and then the samples were put into methylene blue solution for photocatalytic experiments.

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The strong electron-phonon interaction in 2D perovskites would lead to the formation of trap states. The electron-hole pairs or free excitons may be trapped by these trap states and affect the optical and electrical performance. According to photoluminescence measurements, we found that the recombination processes were governed by a free exciton channel as well as two self-trapped exciton channels. Furthermore, the transition rates between each state can be understood by time-resolved photoluminescence measurement and numerical fitting of the rate equations.

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We use inorganic perovskite CsPbBr3 nanocrystals coated on SiO2 microspheres, with the excellent luminescence properties of CsPbBr3 nanocrystals as an excellent optical gain medium, as well as the excellent geometric properties of spherical cavities to provide light to generate total reflection and reduce energy loss. At room temperature, the whispering-gallery mode was observed.

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Non-volatile memory will play a significant role in the progress of the next-generation of electronic products. In this paper,switching properties of Al/MgO/ITO/Glass resistive random access memory device were successfully demonstrated. Conduction mechanisms were investigated from current-voltage (I–V) graphs of RRAM devices, Under different metal oxide film thicknesses, the measurement results show different distributions of resistance values, among which the device with MgO thickness of 20 nm is the most stable probability distribution.

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In this study, we investigated the change of optical reflectance of the samples with nano-size phosphors layer on the silicon substrate with Al2O3 (80 nm) by dip coating silicate solution with different phosphors concentrations (3, 5 wt%). To achieve a uniform distribution of phosphors on the samples, we also study the surface of Al2O3 layer with and without hydrophilic process under UV light illumination before dip coating.

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