Session Index

Bound states in the continuum could be realized by the metasurface with high Q-factor resonance. It uses a pair of rectangular bars to form two surface lattice resonances with destructive interference, so that Fano resonance occurs. In this study, the symmetry of the structure was broken to produce chirality and maintain the high Q-factor. We also use internal excitation to analyze the localization of the electric field and the polarization of the emission. This result can confirm that the high Q-factor can be maintained regardless of external or internal excitation after the structure symmetry is broken.

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Developing high-performing and silicon compatible mid-infrared photodetectors will greatly benefit mid-infrared silicon photonics applications. We proposed a new type of hybrid photodetector, which is composed of black phosphorus / molybdenum ditelluride van der Waals heterostructures integrated with a silicon-on insulator waveguide. Our device could exhibits high responsivity, ultrafast rise and decay time in the mid-infrared spectral range. The results show its great promise for mid-infrared on-chip sensing applications.


 

A newly developed asymmetric quarter-wave-shifted (QWS) DFB based electro-absorption modulator lasers (EMLs) are proposed here to overcome the challenging issues for the former symmetric AR-AR schemes, which suffer from performance degradation due to the external optical feedback and its output efficiency. With HR-AR structure, an asymmetric QWS-EML can maintain a high dynamic single-mode yield of 89.19% and average Q-value of >20.8 even with strong reflection from EAM output facet. Regarding these improvements, we admit that the advanced MQW laser technologies in terms of asymmetric QWS DFB based EMLs can affords the cost-effective solution for the forthcoming 800G or 1.6T Ethernet

 

We investigate a tunable plasmonic structure to enhance perovskite material’s fluorescence with nanosphere self-assembly method, magnetic sputter system, thermal evaporation system, and chemical solution method. When perovskite on the structure with no silver particle, its fluorescence enhancement is 2.86 times. When the perovskite on the structure with silver particles, its fluorescence enhancement is 27.41 times, respectively.

 

A one-bit transmission and optical output power to DC voltage bias curve (P-V curve) on the asymmetric-arm Mach–Zehnder Modulator (MZM) are demonstrated. The one-bit signal amplitudes are 41.63 µW and 42.81 µW over VDC are 1.1 V and 3.2 V, and P-V curve slopes are roughly 0.218 and 0.444.

 

In this research, a polarization actuated graphene photodetector was demonstrated
via surface plasmon polaritons (SPPs) detection. The designed symmetric nano-structure
guides the SPPs to the graphene photodetector due to local carriers heating. The excited hot
carriers were separated and driven via external and internal electric fields, generating a
photocurrent. The micro-scale directional coupler was based on a two-wire transmission line
that supports a symmetric and an antisymmetric modes. This yields unidirectional propagating
surface plasmons tuned by different polarizations of light. The contrast of photocurrent from
different polarizations was 300 %.

 

We integrate 1D photonic crystal nanobeam lasers onto SiNx waveguides by high precision transfer printing technique. With asymmetric PhC lattice and tapered structure design, we realize highly efficient light coupling in this heterogeneous integration and investigate the integration misalignment tolerance for the light coupling.

 

We experimentally demonstrate the voltage modulation of plasmonic nanolasers on graphene-insulator-metal (GIM) platform at room temperature. The threshold and peak position of lasing peak could be tuned by gate voltage. The diminishing of lasing intensity, and the wavelength shifts of peak positions were observed when the applied voltage was changed.

 

Dual-phase two-color emissions of multilayered GaTe positioned at 1.588 and 1.652 eV are simultaneously detected by micro-photoluminescence measurement at 300 K. The lower-energy peak may originate from the hexagonal GaTe (H-GaTe) phase while the higher-energy luminescence might come from monoclinic GaTe (M-GaTe) phase and which are verified by micro-thermoreflectance and HRTEM. TRPL and AFLM of the multilayer GaTe indicated that the averaged decay lifetime of the H-GaTe is larger than that of the M-GaTe. Polarized micro-Raman and polarized micro-PL measurements shows that M-GaTe has higher extinction ratio and lower symmetry than that H-GaTe.

 

Metasurfaces have attracted great interest because of their ability to control the amplitude, phase, and polarization of electromagnetic waves. In this study, we first demonstrate emission angle covering ±20° × ±20° from a metasurface-integrated PCSELs array with a very compact size.

 

In this study, the proposed phase gratings are fabricated by the uniform lying helix (ULH) textures of cholesteric liquid crystals (CLCs). With the characteristics of LCs, an electrically tunable phase grating is realizable under ULH textures. Besides, the effect of the LC dimer, CB7CB, to ULH textures is investigated.

 

In this study, we demonstrate the High-Contrast Grating(HCG) that fabricated on the semipolar substrate with aluminum deposition shown better polarization control ability and achieved degree of polarization(DOP) value to 0.75. Compare to the p-type gallium grating and nonstructural devices, the grating with aluminum deposition shows the best performance of measurement and simulation.

 

We demonstrate a dual-wavelength guided mode resonance (GMR) filter based a holographic-defined moiré waveguide grating structure. As-realized GMR filter exhibits two resonant wavelengths (561 and 632 nm) for TE-polarized light.

 

Vanadium dioxide (VO2) is one of promising Phase change materials (PCMs) presenting the insulator-metal transition (IMT) with strong contrast in physical properties, low critical temperature, ultra-fast transition and continuously tunable characteristic. In our work, we apply VO2 onto ITO glass as a memory layer so as to develop a novel approach to quantify the correlation between IMT behavior and the geometry-dependent Joule-heating effect. The demonstration of two-terminals memory device provides a new way for nanophotonics and advanced optoelectronics device. Notably, this approach also reveals the significance of thermal engineering for efficiently obtaining phase transition of VO2.

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In this paper, we study active control of photonic crystals. And we consider photonic crystals of finite thicknesses which is made of infinitely long and periodical dielectric cylinders. Such systems host waveguide modes whose photonic band structures are determined by dielectric geometries. And the optical properties reflect their photonic band structures. Therefore, we investigate how gain and loss affect reflection and transmission. Then we find that, after adding the lossy material, the optical properties of the photonic crystals have the lower peaks on transmission and the crossing of transmission and reflection have a red shift.

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In this study, we integrated monolayer tungsten diselenide (WSe2) on a flexible substrate with the one-dimensional (1-D) silicon nitride (SiNx) photonic crystal (PhC) structure, and analyze optical characteristics of the device.

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Here, a self-steering lasing emission from a defect-mode sandwich-like resonator consisting of photomechanical deformable azobenzene cholesteric liquid crystal elastomer is demonstrated. The output lasing emission can be fast steered by UV irradiation within a wide angular tuning range of approximately ± 57°.

 

In this paper, we investigate the spectral characteristics of random lasing behaviors via the Monte Carlo simulation in a system of dye solution with dielectric scatterers. The calculation model not only shows the correspondence to the experimental measurements, but also suggests that lasing threshold is highly dependent with the pumping spot size and scattering mean-free path in disordered medium. Furthermore, we simulate the effect of single-particle Mie resonance on emission spectrum, discussing the wavelength tunability of random laser.

 

We demonstrate an industry-compatible method to fabricate wafer-scale metasurfaces on freestanding membranes. The method is based on deep-UV lithography and capable of producing both of plasmonic and dielectric metasurfaces for various functionalities. The reported metasurfaces show ideal operation efficiencies for high-quality-factor resonances, light focusing and polarization control, and biosensing.

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We experimentally demonstrate basic Boolean operations and conventionally required serial gate operation can be converted to pure parallel operation in a combinational circuit. Two particular arithmetic circuits, a half-adder and a half-subtractor, are designed and realized.

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In this research, the largest absorption ~90% at the communication wavelength (λ = 1547 nm) was demonstrated by germanium nanohole metasurface with subwavelength thickness (~ 310 nm). By tuning the different hole depth in Ge metasurface arrays, we also can get the tunable Q-factors from 70 to 126.

 

It is known that the wavefront will be disturbed through a display panel. A phase conjugation metasurface is proposed to eliminate the disturbance arising from the periodicity of a panel. The corresponding under-display wavefront error can be significantly reduced via the wavefront optimization method.

 

In this study, we designed a sensor chip-based on Al films as an adhesive layer and Ag/Au films as a sensing layer for surface plasmon resonance (SPR) sensor and demonstrated that the structure shows a better performance until 1.8-fold higher figure of merit than conventional SPR chip based on Cr/Au films.

 

A change in density due to increase in temperature is one of the basic characteristics of a material and change in density can also leads to change in the refractive indices. This phenomena can be used in a controlled way to fine tune Localized Surface plasmon resonance(LSPR). In our work we fabricate an on-chip microheater where the temperature depends on the input voltage. In this work the LSPR is fine tuned indirectly by applied voltage with changing surface temperature. The outcomes of this experiment are also verify and reconfirmed by heating the substrate externally.

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We reported a broadband reflector based on polymer-stabilized cholesteric liquid crystals whose bandwidth is broadened by applying the direct current (DC) bias and then photo-polymerizing. The reflection band can be further extended toward the longer wavelengths by applying the DC voltages.

 

We demonstrate a tunable scan lens based on a 30-element optical phased array on the InP integrated photonic platform. We develop a phase calibration procedure based on the genetic algorithm, which optimizes the driving signals of the optical phased array to form focused spots. We show dynamic scanning of the focused spot, including changing the focal length to 100 μm and 75 μm, as well as introducing different lateral offsets. The minimum measured spot size is 2.72 μm, which matches well with the simulation.

 

We calculate the optical characteristics such as band structures and transmission and
reflection of plasmonic crystals with square lattices by using the finite difference time domain
method. The time-domain method provides a stable calculation of band structures for lossy
materials such as metals. We applied random source excitation to find all the possible modes.
Such an approach is advantageous in finding localized modes. We obtain the band structures of
the plasmonic crystals and the reflectance and transmittance of the plasmonic crystals both in the
TE and TM cases.

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Lead-free cesium tin halide (Cs2SnBr6) double-perovskite nanocrystals (DPNCs)
having cubic symmetry were synthesized and investigated. The prepared DPNCs and blue
phosphor were mixed with polydimethylsiloxane packaging in 365 nm UV light emitting
diodes (LEDs), which were used to fabricate environmentally friendly candlelight LEDs.

 

We fabricated a InGaAsP microdisk cavity with a photonic crystal feedback waveguide nearby and further investigated the lasing characteristic between it and a microdisk laser. The enhancement in the circular polarization degree of laser emission is achieved by integrating the microdisk laser with the waveguide.

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We measure the transverse band gap of blue phase liquid crystal(BPLCs) by observing the reflection spectrums of BPLCs through the fiber-assisting measurement system. By analysing the change of spectrum caused by temperature or electric field, we can verify the photonic band gap(PBG) model of BPLCs

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How to develop efficient red-emitting organometallics of earth-abundant copper(I) is a formidable challenge in the field of organic light-emitting diodes (OLEDs). Here, a red Cu(I) complex, MAC*-Cu-DPAC, was developed in a carbene-metal-amide motif, achieving satisfactory red emission, a high photoluminescence quantum yield of up to 70%, a high horizontal dipole ratio of 77%, and a sub-microsecond lifetime. The resulting OLEDs delivered high external quantum efficiencies of 21.1% at a maximum and 20.1% at 1000 nits, together with a red emission peak at ∼630 nm. These values represent the state-of-the-art performance for red-emitting OLEDs based on coinage metal complexes.

 

We demonstrate 1D photonic crystal (PhC) lasers embedded in a polymeric thin film, which can attach to any object's surface. Owing to this feature and the nanoclamp design with strain shaping, the PhC laser inside shows significant wavelength responses to the applied bending and pressing in experiments.

 

We propose a novel Archimedean spiral plasmonic lens (ASPL) consisting of a spiral slit and multiple circular grooves for far-field focusing. The simulation results show the focusing properties can be modulated by different arrangements of the groove widths. The ASPL with decreased groove width design exhibits the largest focal length of 1.26λ, the strongest focusing intensity, and subwavelength resolution of 0.42λ.

 

We carried out a comparative study to evaluate the feasibility of gold nanosphere and nanodisk to enhance the deep-red emitter emission. As a result, gold nanospheres and nanodisks with diameters greater than 50 and 60 nm are suitable for increasing the deep-red emitter quantum yield, respectively. Interestingly, nanodisks show greater radiative enhancement than nanospheres.

 

Hybrid Ag/Au/AgCl nanomaterials are successfully synthesized by photoreduction using the ferroelectric template. The Raman signals are effectively enhanced by electromagnetic and chemical mechanisms. The superior performance includes the limit of detection as low as 1.57×10^-9 M and the ultra-high enhancement factor of 6.92×10^9.

 

We produce the distributed feedback (DFB) laser from dye covered biopolymer with one dimensional grating. Through the pump of Q-switched laser, the emission peak and FWHM of DFB laser are 583.2nm and 0.30 nm . After embedding of silver nanoprisms The blue shift of emission peak and narrowing of linewidth have been produced.

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With the advent of two-photon polymerization, a direct laser writing is unique, flexible, and cost-effective fabrication technique for three-dimensional structure. In this paper, we have demonstrated the customized structures, such as grating、microfluidic and spiral suspension structures for many applications in the diversified scientific and industrial fields.

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The plasmonic Ag nanoparticles are photoreduced using ferroelectric templates and effectively transferred to the PMMA film by a peel-off process for the parathion detection on curved surfaces. The produced flexible SERS substrate owns intensive hotspots with ultra-low limit of detection 1.76×10^-9 M and high enhancement factor 3.25×10^8.

 

In this study, the Ga2O3 thin films were grown on sapphire substrate by RF magnetron sputtering and hydride vapor phase epitaxy technique. Then, the metal-semiconductor-metal (MSM) photodetectors were fabricated and the optoelectronic properties were studied. The Ga2O3 photodetector using hydride vapor phase epitaxy technique exhibits lower dark current and better photo responsivity.

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In this research, we demonstrate hybrid plasmonic waveguide (HPWG) have lower propagation losses and higher effective refractive index than the metal-insulator-metal (MIM) plasmonic waveguide, but still provide high confinement characteristic.

 

The structure optical and electrical properties of ZrS2-xSex single crystal with composition x=0, 1, and 2 were grown by CVT method with Iodine as the transport agent. The HRTEM and XRD revealed that ZrS2-xSex were crystallized in 1T structure with lattice constant increase as the doping increased. The energy-gap of ZrS2-xSex were shifted to lower energy as doping increased. Two Raman vibrational modes were detected at 300K. Resistivity and Hall-effect measurement indicated that the series are N-type semiconductors. Thermoelectric of ZrS2-xSex was investigated from 25 to 300K. At 300K, ZrSe2 demonstrates the highest ZT value of 0.08 among the series.

 

Having the capability of manipulating the valley degree of freedom is essential for the future valleytronics applications, and such devices could provide a new way of data encoding and information processing. We developed the novel van der Waals heterostructures that incorporate a Fe3GeTe2 ferromagnetic tunneling contact. The contact can inject spin-polarized carriers and consequently lead to valley polarization of transition metal dichalcogenides (TMDs), as confirmed by our helicity-dependent electroluminescence measurements. Our results show the possibility of electrically manipulating the valley degree of freedom of TMDs.

 

In this work, we experimentally demonstrate an array of single-layer plasmonic metasurface with a linear cross-polarization conversion efficiency reaching ~22.9%, which is comparable to the theoretical limit. The high polarization conversion efficiency arises from the Fano-like coupling of toroidal dipole and quadrupole resonances.

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A chip-level meta-corrector stacked on CMOS image sensor is proposed to improve the optical performance of a Cooke triplet. It is theoretically demonstrated that the spot size of a Cooke triplet consisting of three pieces of spherical lenses can be significantly reduced from 43 um to 0.565 um

 

We demonstrates an advanced planar phase modulator called Bragg-Berry optical vortex generator (BBOVG) based on molecular-motor-doped cholesteric liquid crystals. The BBOVG can generate reflected vortex beams with a wavelength tunable in an ultra-broadband photonic bandgap (PBG) and a sign invertibility of orbital angular momentum, by controlling the pitch and the topological charge of the BBOVG under the UV illumination and applied voltage.

 

This work investigates the correlation between substrate and base angle effects on arrays of Al nanodisks, which unveils a dipolar plasmonic shift and the emergence of two other plasmon modes with ultranarrow bandwidths at shorter wavelengths. The narrow-bandwidth resonance facilitates high Q-factor resonators and a more diffuse electric field, potentially increasing signal resolution in sensing applications and enhancing plasmon-exciton coupling over a wider area in solid-state lighting devices.

 

Phosphor CaAl2O4:Eu2+ coated with carbon quantum dots (CQDs) was synthesized. CQDs were uniformly distributed on the phosphor. CaAl2O4:Eu2+ excited at 335 nm showed blue emission with a peak at 437 nm. Photoluminescence was decreased when CQDs was coated. The effect of CQDs coating on the luminescence of phosphor was investigated.

 

All-solution-process has advantages of convenience and low cost for perovskite light emitting diodes. However, either surface morphology or pre-coated perovskite nanocrystals will be damaged when a layer is spin coated on its top. Here, we proposed an interface treatment that can preserve the integrity of the pre-coated perovskite films.

 

Innate wide bandgap and poor electrical properties of conventional TiO2 photocatalysts limits their application to light-driven CO2 conversion. In this work, we demonstrate and characterize engineered electrical and optical properties of the TiO2 by electrochemical hydrogenation process for the performance improvement of photocatalytic CO2 conversion.

 

A home-made reflectance confocal laser microscopy (RCLM) was used to observe the stacking angles in bilayer graphene system. Data points from images acquired by the RCLM were then analyzed using imagej to investigate the relationship between rotational angles and the light transmittance;
The above-mentioned microscopes are non-contact types, which present high scanning speed, do not need extra sample preparations, and can avoid damages on sample surfaces. These optical approaches are used in this study to observe changes in bilayer graphene,providing convenient and time-saving techniques for future graphene applications and tests.

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Slow-light has attracted more attention due to its high potential applications for optical communications and nonlinear optics. Theoretical investigations of slow-light effect in one-dimensional topological photonic crystals are presented. The study results show that ultra-slow-light of 1.05 m/s group velocity is obtained by this approach.

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In recent years, the development of Optical Vortex has also become a popular research objective, in which the PLASMON VORTEX generated by slits generated by different openings will provide a way to control different structures and obtain Orbital Angular Momentun,and thus observe the strength field and phase distribution. In this simulation, we will first observe the intensity field and phase distribution from a single open slit to the plurality of openings. Second, the slits of different openings are also observe the strength field map and phase distribution. At last, there is a summary about different slit structures for different fields.

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In this study, we propose defect modes produced by two identical distributed Bragg reflectors, which is a one-dimensional symmetric photonic structure with dye-doped liquid crystal in the middle of the sandwich-type cell as a defect layer. The excited emission from the lasing dye will enhance due to the defect modes.

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In this research, we demonstrate hybrid plasmonic waveguide (HPWG) have lower propagation losses and higher effective refractive index than the Metal-Insulator-Metal (MIM), but still provide high confinement characteristic.

 

Two phosphine ligands diphenylmethylphosphine (DPMP) and triphenylphosphine (TPP) were introduced onto cesium lead bromoiodide nanocrystals (CsPbBrI2 NCs) to improve air stability in the ambient atmosphere. The DPMP and TPP-treated CsPbBrI2 NCs were successfully utilized as the red emitter for fabricating perovskite light emitting diodes with enhanced performance and prolonged device lifetime relative to the pristine one. The improved device performance was attributed to surface passivation of perovskite nanocrystals by DPMP or TPP ligands, which reduces non-radiative recombination at the trap sites.

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The photovoltaic performances of ZnO-based perovskite solar cells were studied using ZnO nanorods which were prepared via aqueous solution method at different growth time. These samples were characterized by FE-SEM, UV-Vis-NIR, solar simulator measurements and IPCE measurement to confirm the structural and optical properties by the different nanorod growth time.

 

We design a high sensitive multi-mode plasmonic sensor based on the square ring-shaped resonators containing silver nanorods together with a metal-insulator-metal bus waveguide. The suggested structure obtained by the finite element method showed sensitivity and figure of merit and quality factor of about 2473 nm/RIU, 34.18 1/RIU, and 56.35, respectively.

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The SERS substrate based on ZnO multipods decorated with Ag nanospheres is produced by chemical synthesis and offers high enhancement of Raman signal by electromagnetic effect and charge transfer. The achieved SERS performance for nitrophenol detection includes ultra-low limit of detection of 1.49×10^-13 M and superior enhancement factor of 4.27×10^10.

 

Wide-bandgap semiconductors have attracted much attention in optoelectronics. This work prepared chlorine doped ZnSe thin films by chemical bath deposition. The film shows a high absorption in the blue wavelength region. The I-V measurement shows the Al-ZnSe-Al MSM device has a maximum photo responsivity of 0.486 μA/W at the wavelength of 446 nm.

 

We carried out temperature-dependent photoluminescence (PL) measurements under different incident-powers to examine the optical properties of perovskite thin films. The electron-phonon renormalization, thermal expansion, and the state-filling effect are discussed.

 

We fabricated and characterized a high-sensitivity InP/InGaAs planar single-photon avalanche photodiode (SPAD) with single floating guard-ring and double-diffusion processing. At room temperature, the performance of proposed SPAD chip exhibited as following: dark current of 1.3 nA at 0.9 Vbr, gain of > 10000 at -60 dBm, and linear dynamic range of 55 dB (-60 dBm~-5 dBm). The good linear-mode characteristics of APD chip will be conducive to good working in Geiger-mode single-photon detection performance.

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The influence of the photoalignment on the memory state of nematic-silica-dye suspension was studied. When the photoalignment was executed, the adsorbed azo dyes screened the vertical-alignment effect that was supported by silica networks. The hybrid orientation was stabilized because the azo dyes on the substrate provided a stronger surface alignment.

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We report on the growth of low droplets, highly mismatched GaAsBi alloys on GaAs by MBE. GaAsBi is coherently strained to GaAs and reveals a Bi mole fraction of 4.2 % from RSM result. GaAsBi shows three kinds of Bi compositional depth profile with various Bi/Ga atomic flux ratio. The incorporation of Bi results in a bandgap reduction of 0.3 eV and make the bandgap temperature-insensitive. Temperature-dependent PL shows a signature of localization effect with Bi incorporation.

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A high-performance broadband photodetector based on perovskite/ZnO nanorods was fabricated. The perovskite/ZnO nanorods photodetectors were sensitive to ultraviolet and visible light, while pure ZnO nanorods photodetectors were only sensitive to ultraviolet light. Perovskite/ZnO nanorods composites are promising materials for broadband wavelength detection from ultraviolet to visible light.

 

In this study, the optical and electrical characteristics of the InP-based APD with the same epitaxial-layers and processing parameters but with the different optical-window areas were demonstrated. The dark-current increases with the window area, however, the photo-current density decreases with the window areas increasing when it biased at 0.9 VBR.The fabrication and characteristics of InP/InGaAs SAGCM APD were demonstrated. Impressive lower dark-current and higher photo-current density of 50 μm APDs was obtained. We expected that the performance of 200 μm APDs can be improved through using a transparent conductive oxide film as good passivation and antireflection.

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In this study, the InAs self-assembled quantum dots (QDs) were epitaxial grown on In0.15Ga0.85As/GaAs quantum well by molecular beam epitaxy. The photoluminescence emission wavelength of InAs QDs were observed extending from 1262 nm to 1344 nm with increased dot density in contrast to the InAs QDs grown on GaAs buffer layer.

 

The AlN film was grown on Si<111> substrates by using RF magnetron sputtering at substrate temperature of 600˚C. The AlN film was deposited with varied nitrogen ratio of the Ar: N2 mixture gases of 50, 75, and 100 %. At 100% nitrogen ratio, the crystal orientation of AlN film was <002>, and it had better RMS and hardness.

 

he RF power of 500 W was adopted for the sputtering growth of AlN film on Si (111) substrate with pure nitrogen plasma and varied growth temperatures from 400 °C to 800 °C in this study. Through high-resolution XRD measurement, it is found that the AlN film has AlN (002) crystal orientation and the strongest XRD AlN(002) peak intensity can be obtained at a temperature of 600 °C, indicating the optimum AlN crystal quality.

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This study discusses about Cd free (Zn(O:S)) as an alternative buffer layer applied for CZTS thin-film solar cells. Zn(O:S) thin film was prepared by post sulphurization of RF sputtering-deposited ZnO layers. The samples were subjected to a high-temperature sulphurization at the temperatures ranged from 200 to 300, 400 and 500°C for studying the effect of temperature on the structural and optical properties of the Zn(O:S) thin films.

 

In this study, the Indium composition of InGaAs quantum well of InAs/InGaAs dots-in-a-well (DWELL) structure were studied to improve the dot-size uniformity, dot density and optical properties of InAs quantum dots (QDs). In addition, the density of epitaxial defective coalescent dots was also found significantly reduced as decreasing the Indium composition of the InGaAs well.

 

Quantum dot light-emitting diodes (QLEDs) using nickel oxide (NiOx) thin film or nanoporous layer (NPL) as the hole injection layer (HIL) were fabricated for comparison. The obtained NiOx NPLs have sponge-like nanostructures that possess larger surface area to enhance carrier injection and to lower turn-on voltage of devices, as compared with the NiOx thin film. The best QLED was achieved with 30 nm-thick NiOx NPL, revealing a maximum brightness of 68,646 cd m-2, a current efficiency of 7.60 cd A-1, and a low turn-on voltage of 3.4 V.

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In this study, we carry out numerical investigations on optical properties of tripods of metallic gyroids. Extinction and circular dichroism spectra are presented to examine how chiro-optical properties evolve under different structural parameters and excitation conditions. The results provide physical insights towards the understanding of chiral plasmonics in metallic gyroids.

 

In this study, we present the preparation and characterization of DNA resistive switching devices on a flexible substrate. The curved DNA devices exhibit resistive switching responses of multiple sweeping cycles and morphological properties of the bending devices are also examined. Our results show that DNA biopolymer holds great promise for the applications of flexible bio-electronics.


 

Novel SERS substrates integrated with optical waveguides for excitation and collection of Raman signals are proposed. The LiNbO3 ferroelectric template with zinc-diffused ridge waveguides produces silver nanoparticles by photoreduction for Raman signal enhancement. The SERS detection for R6G reveals limit of detection of 1.58×10-9 M and enhancement factor of 2.84×109.

 

We present a Moiré metalens-based optical sectioning fluorescence, which utilizes the telecentric design to obtain constant magnification images over a long axial scanning range. The Moiré metalens consists of two complementary phase metasurfaces. Furthermore, the imaging system incorporates structured illumination to capture the HiLo optical sectioning images.

 

In this study, high-performance indium–gallium–zinc oxide thin-film transistors (IGZO TFTs) with a dual-gate (DG) structure were manufactured and the device operation performances were improved by using rapid thermal annealing (RTA) process with thermal treatment temperatures ranging from 100 °C to 300 °C.

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This work discusses about the use of Molecular Beam Epitaxy (MBE) to grow InAs/GaSb Type II superlattices (T2SL) on GaSb substrates and focuses on studying the effects of growth at different epitaxial temperatures using the same device structure. Further investigations will be performed to obtain a suitable growth temperature

 

2D material transistors are fabricated on wafer-scale MoS2 films prepared by the two-stage growth procedure. RF sputtering and the ALD are adopted to deposit Mo precursor on sapphire substrates before sulfurization. The higher field-effect mobility value of the MoS2 transistor fabricated by using ALD reveals that a uniform precursor distribution will help to form MoS2 films with improved crystallinity. With improved crystallinity of contact electrodes grown at higher temperatures, enhanced device performances are observed. By using antimonene as the contact metal, high field-effect mobility 2.03 cm2/V·s and > 105 ON/OFF ratio is observed for the MoS2 transistor prepared by ALD.

 

An IR cut filter, consisting of metasurface embedded in pigment layer, is designed and fabricated. Via the absorption enhancement provided by the metasurface, the thickness of the pigment layer can be significantly reduced which benefits a small pixel CMOS image sensor.

 

Inputting an OOK can be used to increase the degree of change in the depletion region of silicon-MZM, increasing the modulation power from 0.4mW to 0.6mW, which can improve the clarity of signal transmission, thereby increasing the transmission frequency, and reducing the modulation bias from 3V to 2.6 V, can reduce power consumption.

 

Hybrid material design is required to extract broader spectrum of performance in the field of optoelectronic devices, such as photodetectors (PD). We report hybrid PD based on two-dimensional (2D) graphene, and MoS2 in composite with 0D upconversion nanoparticles (UCNPs), and 1D AuNRs. The objective is to improve the poor broadband responsivity of the semiconductor based devices. Careful design of the PDs with high quality Graphene/MoS2, UCNPs (for NIR photoresponse), and AuNRs (for faster response times) yielded high Responsivity ~10^4 A/W (using Graphene/UCNPs PD), Detectivity ~ 10^15 Jones (using MoS2/UCNPs PDs), and a response time of 80 ms (using Graphene/UCNPs/AuNRs PDs).

 

We design and fabricate all-silicon, polarization-independent metalenses operating at 1 THz. The metalenses consist of 180-μm-tall pillars arranged in a hexagonal lattice. We engineer the phase profile by varying the pillar diameter. By using pillar diameter from 35 to 90μm, we obtain full 2π phase coverage. We perform full-wave 3D finite-difference time-domain simulation to obtain the focusing intensity distribution and demonstrate diffraction-limited performance. We fabricate the metalenses with photolithography and bosch plasma etching. The measured focusing efficiency of the fabricated metalens is 46.1 %.

 

Based on the Lorentz reciprocity theorem, we propose a generalized parametric space for any parity-time (PT) symmetric photonics. With the general parametric space, we can indicate complete information on broken symmetric phases, exceptional point, and reflectance. Quite counter-intuitively, we find PT-symmetric photonics can support isotropic reflectance and optical pulling forces.

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