Session Index

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.

  Preview abstract

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.

  Preview abstract

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.

  Preview abstract

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.

  Preview abstract

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.

  Preview abstract

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.

  Preview abstract

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.

  Preview abstract

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.

  Preview abstract

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.

  Preview abstract

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.

  Preview abstract

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.

  Preview abstract

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.

  Preview abstract

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.

  Preview abstract

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