Session Index

We report the fabrication and property of multifunctional electrospun nanofiber chemosensor and perovskite based light-emitting diodes. RGB full-color-switchable chemosensors that are able to simultaneously detect pH and Hg2+ and are based on highly porous fluorescent electrospun nanofibers. Perovskite QDs embedded into polymeric to increase the photostability of light emitters for applications to lighting and backlight displays.

 

μ-LEDs with chip size down to 10×10 μm2 were achieved using a laser direct writing technique. Both the increased current density and blue-shifted emission were observed due to the downsizing effect. The EQE of 10×10 μm2 μ-LED was 18.8%, which is favoring the high-resolution μ-displays.

 

In this work, the deep ultraviolet light-emitting diodes (DUV-LEDs) with multi-quantum wells (MQWs) constructed using 5 pairs of a gallium oxide (Ga2O3) well and an aluminum oxide-doped gallium oxide (Ga2O3:Al2O3) barrier were fabricated. According to the electroluminescence measurement of the DUV-LEDs, the peak wavelength of 243 nm was obtained.

 

A light-emitting diode luminaire with light weight, energy saving, and low cost by using nine optical modules to produce a projection distance of 3.1 km with driving power of 41.8 watts has been verified by precise experiment.

 

Characteristics of red quantum dots light emitting diodes (QLEDs) with NiOx hole injection layer (HIL) prepared by sol-gel method and Poly-TPD as hole transport layer (HTL) were demonstrated. The performance enhancement of QLEDs with NiOx HIL exhibited the maximum luminance (Lmax) of 64,244 cd/m2.

 

The InGaN active region contains a large amount of indium to emit red light. The high-In-content InGaN has a large lattice mismatch to the p- or n-GaN layers, resulting in the introduction of a huge number of defects, interface roughness, and weaker light emission. However, we have improved the performance of red LEDs by introducing AlN/AlGaN barrier layers among InGaN QWs. Such strain control is the crucial point to realize higher efficiency.

 

The GaN ultraviolet light emitting diode with a porous AlGaN distributed Bragg reflectors and Graphene/ITO transparence conductive layer was fabricated through the Graphene transfer-printed process. High efficiency DBR-LED with Graphene/ITO bilayers was observed due to high current spreading process by adding the Graphene on the ITO conductive layer.

 

In this work, graphene oxide with different oxidation levels was prepared. Various optical characterization tools were used to analyze graphene oxide with different oxidation levels. We would like to investigate the effects of oxidation levels of graphene oxide on carrier lifetime.

 

This study applied CO2 laser and solid state reaction to completely transform precursor into Y3Al5O12:Ce (YAG:Ce), exploring the crystal structure and microstructure. YAG:Ce grains grow largely (1500%) as compared to the solid state reacted or laser sintered ones. Transmission electron microscopy revealed round particles in YAG:Ce grains and at boundaries.

 

In this study, Poly(9-vinylcarbazole) (PVK) and Poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl)diphenylamine)] (TFB) were used as the hole transport layers (HTLs) for solution-processed quantum-dot light-emitting diodes (QLEDs) accompanied with MgZnO nanoparticles (NPs) electron injection-transport layer (EIL/ETL). QLEDs with TFB HTL demonstrated higher maximum luminance (Lmax) of 6,001 cd/m2 than that of PVK.

 

To have a better understanding of strain distribution in GaN-based LED structures, three-dimensional strain analyses were conducted on a series of samples with different epi-layer thickness, and the tendencies of strain evolution from substrate to sample surface were compared.

 

The effect of Sn content on the optical properties and composition of thermally evaporated Cu2ZnSnSe4 thin films on FTO substrate is investigated. When Sn content decrease too much, it led to that the grain size of the surface of the films become small and the band gap reduce a little.

 

We used the SolidWorks software package to develop modules and processed simulations for a novel light-emitting diode mosquito catching system, which were then imported into TracePro. Optical simulation was conducted to investigate the mosquito trapping efficiency of the proposed modules. The results were compared to optimize mosquito trapping efficiency

 

In this study, we propose a methodology to measure the thermal conductivity of polyethylene-terephthalate (PET), a plastic substrate utilized in flexible organic light-emitting diodes (FOLED). By means of the measured thermal conductivity, we can further predict heat distribution of a FOLED.

 

In this work, a source metal trench for GaN based HEMTs toward the buffer region to alleviate trapping of channel carriers in the buffer region is proposed. The results indicate less dynamic on-resistance increase at higher drain and gate stress voltages of the device with source trench in the mesa.


 

We have demonstrated dual-gate AlGaN/GaN high-electron-mobility-transistors (HEMTs) by comparing with single-gate AlGaN/GaN HEMTs. In terms of current collapse characteristics, the dual-gate AlGaN/GaN HEMT shows a small change rate in Ron at various off-stress-bias which means the dual-gate structure can mitigate the effect of current collapse.

 

The unavoidable blue light hazard that caused by overheat in phosphor-converted white light-emitting diodes was solved effectively by utilizing of thermal-chromaticity material. The hazard to the user's eyes is effectively prevented and simultaneously user is reminded to replace the new lamp.

 

Single crystal Phosphor provide excellent conversion efficiency and thermal stability. However, its unique optical properties of high transparency and high refractive index cannot effectively provide uniform mixed white light. We proposed different patterned structural designs and they can perform their best performance in different lighting applications.

 

Three psycho-visual experiments are carried out to investigate the visual afterimage characteristics of high luminance LED with different sizes of dot matrix under dark surround conditions. As a result, the intensity level and the use of a diffuser obviously influence the visual characteristics of the afterimage.

 

The temperature of LED surface decreased by adjusting width and height of heat sink, from 90 to 83.6°C and from 96.9 to 80.7°C, respectively. Compared with width, adjusting height of heat sink significantly reduce the temperature by 9.6%

 

Four surface-modified and hence positively-charged metal nanoparticles (NPs) of different localized surface plasmon resonance wavelengths are synthesized for linking with negatively-charged, red-emitting colloidal CdZnSeS/ZnS quantum dots (QDs) on the top surface of a blue-emitting InGaN/GaN quantum well light-emitting diode through electro-static force. The metal NP-QD linkage leads to a short...

 

The leaf-structures are patterned onto top surface of a LED to reduce the total
internal reflection at the smooth interface between the encapsulant and air. The optical
characteristics of the LED covered with the replication of leaf surface structure are measured to
verify the enhancement of the LEDs.

 

Mixing different ratios of perovskite CsPbI3 quantum dots and Trioctylphosphine oxide (TOPO) solutions to explore the difference between them, and further explore the effects of doping TOPO and adding UV-type QD optical glue on perovskite CsPbI3 with TOPO quantum dots, and apply it to color conversion devices.

 

The ICBA:modified C60 electron transport layer (ETL) is proposed for the PeLEDs. As a result of improved perovskite/ETL interfacial quality and uniform carrier distribution within the MAPbBr3, the improvement in the output luminance of the PeLEDs is achieved. Furthermore, PeLED-based optical communication is shown to be feasible.

 

Here we propose Si substrate removal technology for HEMTs to alleviate RF loss. By removing the Si substrate, the power gain cut-off frequency is improved mainly due to a higher output resistance. Finally, we develop a small signal model that includes parasitic elements of the Si substrate.

 

This study evaluates users’ attention levels under different office lighting environments by utilizing electroencephalography and self-evaluated questionnaires. The signal processing involves the combination of Hilbert-Huang transform, probability density function towards spectral power, and receiver operating characteristic curves with their area under the curves.

 

Enhancing device efficiencies of the white light-emitting electrochemical cells (LECs) is realized by employing substrates with embedded diffusive layers containing scattering TiO2 nanoparticles. The maximal external quantum efficiency and power efficiency of the white LECs employing the proposed diffusive substrates reach 22.0% and 41.6 lm W-1, respectively.

 

This paper reports an optical structure design method with the predicted performances of blue organic light-emitting diodes with high blue index. By adjusting the thickness of transport layers, the electroluminescent spectra could be narrowed and enhanced. The blue index could be increased from 71 to over 120.

 

The β-carotene was encapsulated in remote yellow phosphor layer to achieve the white light LEDs with low correlated color temperature (CCT).By combining the yellow phosphor and β-carotene with the blue LED chip, the white light emission of the white LEDs with improved color rendering index (CRI) can be obtained.

 

The plasmonic Dicke effect means a cooperative emission mechanism of multiple light emitters when they are simultaneously coupled with the same surface plasmon (SP) mode of a metal nanostructure to achieve a higher collective emission efficiency. We compare the enhancements of emission efficiency among a series of SP-coupled InGaN/GaN quantum-well..

 

The correlated color temperature, color rendering index, and luminous efficacy of white LEDs with cyan, green and red phosphors in silicone/yellow phosphor in glass at 350 mA were 4200K, 90.9 and 76 lm/W (increase 18.4%), respectively. WLEDs with uniform SPD have improved luminous efficacy through the new phosphor configuration.

 

Since there are many materials which will absorb ultraviolet light, therefore, people are finding different ways to improve luminous power of UVC LEDs in recent years. In this work, we manufacture the omnidirectional reflector on UVC LEDs, which is one of the methods to improve luminous power of UVC LEDs.

 

in this work, a chip on board (COB) was used as a surgical lamp light source.it was found that the center illumiance was 66122 lux. on the other hand,the d50 and d10 was 98 mm and 164mm,respectively.In other word, the d50/d10 was 0.59 (i.e., meet regulation,0.5)

 

This paper investigates the infrared absorption behavior of solid suspended particles in a quantitative way. By using near infrared spectroscopy and partial least squares regression (PLSR), we can explore the changes in concentration caused by the internal transmission of IR light in a real smog-filled environment.

 

In this work, a half mirror with an Al film was formed by using a thermal evaporation. Furthermore, the proposed half mirror can effectively achieve a good mirror effect. In other word, a deep mirror effect can be formed by using an Al mirror and an a half mirror.

 

Light is a non-pharmacological method to improve the sleep cycle, wakefulness, and quality of life. Based on ESP32 micro-controllers, interacting through ESP-NOW protocol. The hardware has been developed to interact with and control 8 LED strips to produce white light with a time-varying CCT.