This study demonstrates a w-LED with the novel combination of blue LED chips, transparent glass substrates and phosphors with PDMS thin film. The flip-chip bonding technology is applied to facilitate this design. The ZrO2 nanoparticles are also doped into the PDMS film to increase light scattering and the heat dissipation to enhance the luminous efficiency and reduce the surface temperature.

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In this study, a labview program is designed to analyze the electro-optical properties , which are measured by the high responsivity of silicon photo detector. To compare with the traditional spectra colorimeter, the long intergral time of dark current can be reduced to further improve the measurement accuracy for OLED device.

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The flat-top pyramidal patterned sapphire substrates (FTP-PSS) have been fabricated for the growth of epitaxial structures of GaN-based light emitting diodes (LEDs). In comparison to the LED on conventional sapphire substrate, there is 61.35% enhancement in the output power (@350 mA) for the devices on FTP-PSS.

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In order to know the broadband spectrum process of TPSBF, we designed a series of controlling experiment have been performed to externally and internally modulate the TPSBF aggregation. The results were measured by MALDI-TOF, TGA, and PL. These experimental results that the broadband spectrum process is responsible for the aggregation induce emission(AIE) phenomena.

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An analytical form of the rapid estimation of thermal resistance method is proposed using the shape factor. The shape factor is function of the radius of a heat source and geometry of the substance. This form can deal with single layer and composite layers structures.

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We proposed an analytical model of the phosphor converted Light-emitting diodes (pcLEDs) with multiple phosphors. It is found that the modeled spectral power distribution is in good agreement with the measured of spectral power distribution of pcLED.

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To investigate the afterimage characteristics induced by high luminance LED under dark surround conditions, three psycho-visual experiments were carried out. The results suggest that intensity of illumination, exposure time and luminance of background are the primary factors influencing characteristic of afterimage

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We investigated the blue phosphorescent organic light-emitting diode (OLED) with different hole-injection layer, MoO3, WO3 and Poly(2,3-dihydrothieno-1,4-dioxin)-poly(styrenesulfonate) (PEDOT:PSS). OLED with PEDOT:PSS HIL exhibited the highest efficiency of 53.17 cd/A and 43.69 lm/W.

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A high efficiency blue phosphorescent organic light-emitting diode (PhOLEDs) was successfully fabricated by using a new host material PCT doped with blue emitter FIrpic to exhibit a maximum current efficiency of 47.8 cd/A, a maximum power efficiency 40.3 lm/W, and a maximum external quantum efficiency 21.3 %.

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The ultraviolet (UV) InGaN light-emitting diodes (LEDs) with an p-AlGaN/GaN superlattice (SL) electron blocking layer (EBL) were investigated numerically and experimentally. The experimental results showed that the GaN-based UV LEDs with p-AlGaN/GaN SL EBL had a better performance over the original structure of the bulk EBL which was attributed to the enhancement of EQE and improvement of the electron blocking and hole injection between the multiple quantum wells (MQWs) and the EBL.

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The influences of normal, without, and reversed polarizations on the performance of AlGaN-based deep ultraviolet (DUV) light-emitting diodes (LEDs) are investigated numerically. The simulation results indicate that the optical and electrical performance is deteriorated seriously when the AlGaN-based DUV LED is with reversed or without polarization.

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We reported on ultraviolet light-emitting diodes (LEDs) with different thickness of the electron blocking layer (EBL) to investigate the effect. The experiment results show that GaN-based ultraviolet LEDs with 32 nm thick EBL has the better performance than the original structure with 64 nm thick EBL which is due to effectively block electron leakage and increase hole injection in active region.

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This paper reports the influence of buffer thickness on the reliability of InGaN LED grown on planar and patterned substrate. Experimental results showed that under same defects, LED grown on patterned substrate and thin buffer layer has larger power degradation and voltage increase. We found that thin buffer thickness is the main failure mechanism to cause power degradation.

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 Abstract — Resolving failure origins of AlGaN/GaN light emitting diodes (LED) has received intensive study recently. In this study, formation of GaCO3 caused by carbon contamination may result in deformation of the electrode near the surface and degrade the device. Degradation in electrical properties is observed in I-V characteristics. Forward-bias and reverse-bias EL images are used to trace the damaged areas. Furthermore, focus ion beam (FIB), scanning electron microscope (SEM), energy dispersive X-ray diffraction (EDX) are applied to examine the damaged areas. Results indicate that formation of GaCO3 may deform the electrode, generate the reverse-bias EL and cause the degradation.

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vary-temperature photoluminescence spectra and Time resolved photoluminescence spectra were systematically measured to investigate the multiple recombination pathways in InGaN/GaN Multiple Quantum Wells. The results indicate that the dominant radiative recombination pathways relate to both the localized excitons in In-rich cluster and shallow traps due to well width variation.

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This study investigated the optical design for LED low beam headlight of vehicle. Using the reflector with free-form surface, each part of surface reflected light emitted from LED to certain range of illuminated target. The illumination of low beam headlight is achieved the standard of vehicular illumination.

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This study presents the refractive index of the lens on the light-extraction efficiency of emitter-type light-emitting diodes. In addition, the optical characteristics of emitter-type light-emitting diodes with a dual-layer lens are also investigated.

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The exciton distribution of OLED is calculated with the consideration of exciton continuity equation. To obtain the mobility of the hole and that of the electron, a method of space charge limited current (SCLC) is used. By means of the proposed approach, the distribution of exciton in the emissive layer of the OLED is acquired.

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This work demonstrated that MWNTs could be used as a thermal conductive material for the encapsulation of OLEDs. The heat transfer property depends strongly on the surface morphologies of MWNTs on epoxy. The temperature of OLED with MWNTs backplate could decrease 20℃ comparing to the OLED with conventional encapsulation.

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This study presents a scattered photon extraction structure with a reassembled remote phosphor layer. The experimental results revealed that the output power and luminous flux of the SPE structure LED with a reassembled remote phosphor layer was higher than those of SPE structure LEDs with mixed remote phosphor layers.

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The purpose of this research is to establish an electro-thermal model for the OLED device. We will measure the thermal conductivity to derive the temperature in organic layers, input such result into the equation of electron mobility, and then do experiments to verify the simulated results.

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Abstract—A real time monitoring system of emission characteristics of patterned sapphire substrate (PSS) light emitting diodes (LEDs) consists of a beam energy analyzer and 100X objective. The image of the PSS provides information inside chips. OCIS codes: (120.4640) Optical instrument; (120.4820) Optical system; (230.3670) Light-emitting diodes.

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By considering the effective tail states and field dependents mobility, 1D Poisson and drift-diffusion solver are developed in order to simulate the organic materials, such as BTBP and BTBP doped with FIrpic. Understanding the result of tail state distribution and the field dependent mobility model helps us in modeling organic light emitting diodes.

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