We proposed LEDs with a p-type AlGaN layer as the electron retarded layer (ERL) in front of electron injection layer. From our result, the light output powers at an injection current of 60 mA can enhancement of 9.76%. The rest electrical and optical characteristics of LEDs was also have improved.

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By analyzing the measurement spectral data in detailed, the characteristics including the luminous efficiency, the light decay, the thermal resistance and so on can easily be studied. Thus, the lumen maintenance of high power white LEDs can be explored with a systematic comparison. It is found that the lumen maintenance almost linearly decrease as the driving electric current increases.

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In this work, the spectral analysis has been applied on the thermochromic materials. A quantitative model is established by analyzing the emission spectra of the thermochromism materials. As a result, a novel temperature sensing method and procedure can be further developed based on thermochromism.

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Behavior of thermal decomposition of GaN epilayers in atmospheric pressures was studied. Thermal dissociation reaction of GaN epilayers depends on the annealing temperature. The GaN epilayers is complete dissociation and has a GaO2H reactant on surface of exposed patterned sapphire substrates. We demonstrated that the complete decomposition reaction can be expressed as below equation：GaN(S) + H2(V) + 1/2 O2(V) + 1/4 N2(V) = 1/2 Ga(V) + 1/2 GaO2H(S) + 1/2 N2(V) + 1/2 NH3(V).

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In this study, a micro-lens array on the polymer material is analyzed in flexible LED panel lighting design. According to the simulation result, the improvement of the v-cut structure is more uniform for the panel lighting surface. By the molding method, a prototype flexible LED panel lighting had been demonstrated with uniformity 0.77 at 5.5mm thick module.

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In this study, the LED luminaire with batwing beam shape using in corridor is analyzed. Comparing with the T-bar fluorescent luminaire or lambertian beam shape lighting design, the batwing lighting distribution design in corridor can save more fixture numbers under same illuminance condition. Therefore, the suitable lighting distribution design in the corridor for energy-saving is achieved.

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This work demonstrated that vertically-aligned MWNTs reveal higher moisture content than that of horizontally-distributed MWNTs. However, the network morphology in horizontally-distributed MWNTs seems to prevent the absorbed H2O molecules releasing back in the compartment and then acting with Ca, thus leading to a lower WVTR.

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This paper studied the influence of carrier gas used in p-GaN growth one failure mechanisms of InGaN LEDs. Experimental results showed that LED with a p-GaN layer grown under hydrogen mixed with nitrogen gas, could effectively reduce Mg-H bond formation and defects, which exhibited stable output power and operation voltage.

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In this work, the phosphorescent material TCz1 has been used as the blue-emitting layer for the flexible organic light-emitting diodes (OLEDs). The emission performance of the flexible OLEDs has been characterized and discussed in this work.

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The phosphor with blue chip model is constructed and linked with generalized reduced gradient method in spreadsheet for the LED spectrum control. The parameters of the model are calibrated or defined with the dispenser LED prototype measurement results. Finally, the phosphor model can be used for specific spectrum control.

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3D micro-scaled lenses on light-emitting diodes (LEDs) light engine are realized through ultra-precision injection molding in this study. The geometrical construction of single lens is fabricated using 5-axis machining and has pitch from sub-millimeter to micrometer on curved surface. The radiation pattern is designed to 42∘and the radius of lens is less than 3mm.

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An improvement on reducing the dark area of LED tube lamps has been made using triangular microlens arrays. The influence of nine different heights of triangular microlens on optical power distributions of LED tube lamps from 75 to 90 degrees in the observed planes has been investigated.

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We introduce a type of LED light-gauge steel frame lamp with an adjustable illumination light field that does not require a diffusion plate. Base on the Monte Carlo ray tracing method, this lamp has a good glare rating (GR) of 17.5 at 3050 lm. Compared with the traditional LED light-gauge steel frame lamp (without diffusion plate), the new type has low GR. The adjustability of the illumination light field could improve the zebra effect caused by the inadequate illumination light field of the lamp. Meanwhile, we adopt the retinal image analysis to discuss the influence of GR on vision. High GR could reflect stray light on the retinal image, which will reduce vision clarity and hasten the feeling of eye fatigue.

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The implementation of N2-annealed ALD-grown IZO in an InGaN/GaN MQW LED results in light extraction enhancement and forward voltage reduction. At 20 mA operating condition, N2-annealed n-IZO-coated InGaN/GaN MQW LED was found to show a smaller ideality factor than that of the same LED structure having an ITO TCL.

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The effect of phosphor sedimentation in silicone during isothermal curing on color rendering for WLED is investigated. The CCT changed from 5115K to 5887K and the power efficiency degraded 3.5% under different sedimentation conditions have been observed.

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We calculated the profile of convex and concave microlenses with Lighttool®, and fabricated the heterogeneous microlenses array by using inkjet-printing and 3D-printer. We placed the microlens array on top of LEDs, so as to make the light of LEDs more evenly. Finally, we succeed in constructing the microlens array and an energy saving device

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To get the optimized cost-performance for operating the LEDs, well understanding and well-controlled of the optical-electrical-thermal coupling characteristics were the key issues. In this paper, the coupling model of the optical-electrical-thermal with commercial LED’s datasheet was proposed. The coupling effect of the 3D micro-molded LED was measured and analyzed

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A new carbazole triazole derivative, CbzTAZ, was synthesized to be the host of emitting layer doped with FIrpic inside an efficient blue phosphorescence organic light-emitting diode. This OLED shows the excellent external quantum efficiency of more than 24%.

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In this paper, we demonstrated blue phosphorescence organic light-emitting diode (OLED) with two different electron transporting materials. The highest current efficiency was 23.01 cd/A, and the driving voltage is 9.54 V at 10 mA/cm2.

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Ionic polyfluorene derivatives containing iridium complexes were synthesized. The ionic polymers with PF6 − counterions have better thermal stabilities than those with Br− ones. White light-emitting electrochemical cells based on those Ionic polyfluorenes were fabricated and evaluated.

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In general, the distance of far-field of a light source was defined by the intensity distribution (ID) base on the color spatial distribution (CSD) was assumed uniform. This study compared the relationship between far-field decided by ID and CSD for a non-CSU LEDs. From the results, we found that the far-field decided by CSD was farer than ID.

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We simulate the radiative and non-radiative recombinations in GaN LEDs. It’s clearly shown that, as confirmed by experimental results published elsewhere, Auger recombination dominates the efficiency droop behavior. Besides, current crowding enhances Auger recombination, causing more efficiency droop. Increasing the thickness and doping concentration of the n-GaN buffer layer eases off efficiency droop.

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The purpose of this study was to investigated the evaluation of perceived brightness with different light source-spacing under same luminance level. The interaction of planar light source luminance, spacing of point light source array and viewing distance were investigated. Accordingly, the optimized luminance and arrangement of LED array lighting can be obtained.

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In this study, we develop a method to directly transfer GaN-based light-emitting diode (LED) from sapphire onto flexible substrates by laser lift-off (LLO) process. Polydimethylsiloxane (PDMS) was prepared as a flexible substrate which had the advantages of flexible, low cost, good chemicophysical properties and good optically transparent. We have added the yellow phosphor (cerium doped yttrium aluminum garnet, YAG: Ce) in PDMS and caused the GaN-based LED to send out the white photosource directly. In the experiment, through the phosphor doped with different concentrations and observed electro-optical properties of structures to achieve the effect of white light emitting diode device.

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