Session Index

In this work, we introduce Monte Carlo tree search algorithm for the inverse design of high performance metasurfaces. Comparing with metasurface using gradient phase profile, our approach can diminish the requirements of amplitude variation as well as phase shift coverage, and significantly enhance the angular resolution of beam deflection metasurface.

 

In this research, a large modulated depth (68.3%) at the resonance wavelength (λ = 1647 nm) was demonstrated in simulation. By integrated phase change material into metadevices, a dynamic modulation of absorption was achieved.

 

The amplified spontaneous emission from surface normal of CsPbBr3 quantum dots on a flexible PET substrate with the assistance of the silk firbroin has been demonstrated by the pump of Q-switched laser to reveal a low lasing threshold about 18 mJ/cm2.

 

This research aims to overcome the shortcomings of liquid crystal laser, including photobleaching of dyes and induced thermal disturbance, for moving towards the goal of continuous-wave laser output. The experiments are performed based on DDCLC and DDCLC template samples at various pump energies and repetition rates at a long-termed excitation.

 

We reported a phenomenon of negative differential resistance (NDR) with a typical value of peak to valley current ratio 7 on ITO/NiO/Ga2O3/ITO Si thin film diode. The carrier transport mechanism ascribed to a combined effect of charge detrapping and neutralization processes as one sweeps the voltage polarity.

 

Self-assembled, three-dimensional (3D) photonic crystal (PhC) is a promising material on scientific development. Blue phase (BP) liquid crystalline mesophase with unique nanoscale PhC features, possesses periodicity in 3D. Here, a stretching-tunable BP elastomer photonic bandgap (PBG) free-standing film is fabricated. Additionally, mirrorless laser applications with flexible tunability are also realized.

 

This study has advanced investigated the mechanism and the evolution of etching lift-off monocrystalline silicon nanomembranes from SOI sample by low concentration HF (34mM) in supercritical CO2 in condition of temperature = 60 degree C and pressure = 3000psi.

 

This work demonstrates a high definition video streaming through sub-terahertz link based on a terahertz photomixer. The bit rate of the high definition video streaming is 3 Gbps and the carrier frequency is 150 GHz.

 

The Photoelectrochemical devices that use n-GaN as a working electrode usually deal with recombination/photocorrosion. To overcome this, a thin-layer of NiOx was prepared(sol-gel) and deposited(spin-coating) on the surface of n-GaN(MOCVD). Additionally, KOH is used to convert Ni(OH)2 into NiOOH for activating the surface, which makes NiOx@n-GaN as an excellent photoanode

 

An InGaN-GaN Multiquantum Well(MQW) p-n junction photodiodes with polarization-detecting function were designed and fabricated. With the special structure of photodiode, elliptical nanorods array, polarized light can be detected efficiently without extra component stacked on the photodiode. Results in this study will help to develop a chip-level polarization photodiode detector.

 

We present a novel spatial imaging method to take the surface plasma resonance (SPR) images on nanostructure-based chips. Comparing the transmission intensities between two tunable wavelength bands near the SPR wavelength, and variations of the surface refractive index can be easily measured.

 

The study reports the electro-optical properties of ions-/dichroic dyes-doped nematic LCs (IDdNLC), and the model of the formation of the “chevron patterns” of IDdNLC applied with external fields. The observations under a polarized optical microscope with an analyzer or not, and the polarization-selective absorption-/scattering of IDdNLC are shown.

 

In this study, InAs sub-monolayer quantum dots were grown and capped with InAlGaAsSb. Photoluminescence measurement was used to study the optical properties of the InAlGaAsSb capping layer. Elongated photoluminescence emission wavelength with broadened spectral linewidth were observed for quantum dots capped with InAlGaAsSb compared with the typical GaAs capping layer

 

Amorphous photonic structures attract attention owning to its unique noniridescent optical properties. In this study, we presented three representative structures of amorphous tripod networks generated by two different methods to examine formation of photonic band gap. Our results revealed homogeneity of spacing distribution is critical for gap formation.

 

This paper presents the luminescence properties of Zn2SiO4:Eu3+ nanophosphors
prepared with the sol-gel method. Under excitation at wavelength 394 nm, the Zn2SiO4:Eu3+ showed red emission with a peak at 616 nm. The influence of Eu3+ concentration and sintering temperature and time on the luminescence characteristics of the phosphor was investigated.

 

In this study, we present the stimulus pulse-dependent responses of DNA biopolymer devices, where the conductivity of the device is controlled by consecutive electrical pulses of different parameters. Device behaviors can mimic the synaptic plasticity in the human brain, paving the way towards biomaterial-based artificial synapses in neuromorphic systems.

 

An anti-opal hydrogel sensor capable of identifying L-Tryptophan (L-Trp) is prepares by combining photonic crystals with molecular imprinting techniques. This sensor has a great exclusive-identification for L-Trp, and its concentration can be predicted from the displacement of its reflective peak and the change of the color coordinate positions.

 

In this work, CsPb(Br1-xIx)3 quantum dots with different compositions were prepared and the temperature-dependent photoluminescence (PL) measurements were carried out. To investigate the thermal behaviors of peak energy, linewidth, and emission intensity of the PL spectra, the electron-phonon interaction and thermal expansion effect on the band-gap are discussed.

 

We developed a method to quickly identify the location and determine the thickness of two-dimensional materials on silicon substrates by selecting the thickness of the oxide layer in between. It is important to find optimum oxide layer parameters for functional devices. The thickness dependence of spectroscopic properties was studied.

 

In this study, the ZnS material is prepared by CVD, first we use SEM and EDS to analysis of the material, and then use XRD for more detail observation and analysis, those detect instruments information to show that sulfur and zinc can be compounded ZnS by CVD method.

 

The optical properties of the InAs sub-monolayer quantum dots (SML QDs) were improved by the overgrowth of an InAlAsSb capping layer on the QDs. In addition, the type I energy band alignment of InAlAsSb capped SML QDs was verified by the power-dependent photoluminescence measurement.

 

A photodetector with a simple structure that uses a nanostructured p-Cu2O/n-Si heterojunction is purposed. This device features a high responsivity of 0.55 A/W at a reverse bias of -5 V. The p-Cu2O/n-Si heterojunction also has a high response speed (<10 ms) because there is a built-in potential within p-n junction

 

Extraordinary acoustic transmission (EAT) is investigated numerically using a
square lattice array (SLA) of both-sides-open disk resonators (BSODRs) in a steel slab immersed in water. The BSODR resonance results in low-frequency EAT, and it is shown that the
BSODR’s resonant behavior can be predicted using a spring-mass model.

 

We present the characterization of inkjet-printed DNA biomaterial on paper substrates. PL properties and energy transfer efficiency of DNA inks were characterized with different combinations of dyes, deposition orders, and paper substrates. The results suggest that DNA biomaterial may be a promising candidate to be implemented in inkjet printing platform.

 

This study focuses on the light extraction efficiency of green organic light-emitting diodes (OLEDs). A light extraction layer prepared with nanowires was constructed on the external of OLEDs using the PDMS imprinting technology. The brightness of OLED with a light extraction layer was increased to 13190 cd/m2.

 

In this study, the called “Intermittent Process” is designed to enhance optoelectronic properties of Gallium-doped ZnO thin film, which is defined as discontinuously thin film growth process by inserting the intermittent time. Therefore, there are two main parameters are included, which are Intermittent Number (IN) and Intermittent Time (IT).

 

In this study, the adopted optically switchable cholesteric liquid crystals (LCs) are made by left-handed chiral azobenzene and right-handed chiral doped nematic liquid crystals. Using the photoisomerization of the used azobenzene and polarizers, the smart window can be achieved.


 

The photo-currents in graphene was demonstrated by 2 electrodes with difference thickness of the metals. With the thick polycrystalline gold electrodes at the wavelength = 650 nm, the near-field photocurrent can be detectable even the transmittance is ~ 0.

 

In this study, sandwiching the InAs submonolayer quantum dots in the GaAs/GaAsSb hole-trapping structure can improve the crystal quality and optical performance of InAs SMLQDs.

 

By the intensity dependent PL using the Ti:sapphire laser as a light source, TPA effect has been demonstrated through the power law fitting to reveal the exponent around 2. Through the interferometric autocorrelator using the Ti:sapphire laser, we obtain the pulse duration of passive mode-locked Ti:sapphire laser around 103 fs.

 

The hierarchical ZnO nanorods (ZnRs) were prepared by the two-stage hydrothermal method. The high concentration of HMTA in the precursor can inhibit the lateral growth of nanorods, resulting in a concentrated structure size distribution and excellent verticality,
improved the step coverage problem caused and the electrochromic properties are obviously enhanced.


 

We fabricated lateral Schottky barrier diode and characterized the electrical behavior at different annealing time done on ohmic contact and compared with no annealing. COMSOL simulation was to determine electrons and holes concentration. It was observed that
sample annealed for 60s can withstand the high breakdown voltage up to 1kV.