Publications by authors named "Guoyi Tao"

Here, we propose nanoimprinted patterned sapphire with a silica array (PSSA) with the aim to promote the efficiency of InGaN-based green (∼520 nm) mini-LEDs. According to x-ray diffraction measurements, the threading dislocation density of GaN epitaxial layers grown on nanoimprinted PSSA demonstrates a pronounced reduction compared with the epilayers on the conventional patterned sapphire substrate (PSS). Consequently, a mini-LED on PSSA exhibits a significantly boosted light output power (LOP) in comparison to a mini-LED on PSS.

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Highly efficient indium gallium nitride (InGaN)-based yellow light-emitting diodes (LEDs) with low efficiency droop have always been pursued for next-generation displays and lighting products. In this work, we report an InGaN quantum barrier (QB) with linear-increase In-composition along [0001] direction for InGaN-based yellow LEDs. With the In-composition in QBs systematically engineered, three QB structures including linear-increase QB (LIQB), linear-decrease QB (LDQB) and commonly used flat QB (FQB) were investigated by simulation.

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Pursuing efficient long-wavelength InGaN LED has been a troublesome issue to be solved, which forms interesting subjects for fundamental research, but finds also motivation in extensive applications. Here, we investigate the effect of TMIn (trimethylindium) flux variation for growing bandgap-engineered staggered quantum wells (QWs) on corresponding LED properties and demonstrate the unexpectedly simultaneous increase in light output power (LOP) and emission wavelength. At 20 mA, LEDs based on staggered QWs grown under low flux show an increase of 28% in LOP and longer wavelength compared to that under high flux.

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High-efficiency GaN-based green LEDs are of paramount importance to the development of the monolithic integration of multicolor emitters and full-color high-resolution displays. Here, the InGaN quantum well with gradually varying indium (In) content was proposed for improving the performance of GaN-based green LEDs. The InGaN quantum well with gradually varying In content not only alleviates the quantum-confined Stark effect (QCSE), but also yields a low Auger recombination rate.

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InGaN-based long-wavelength light-emitting diodes (LEDs) are indispensable components for the next-generation solid-state lighting industry. In this work, we introduce additional InGaN/GaN pre-wells in LED structure and investigate the influence on optoelectronic properties of yellow (~575 nm) LEDs. It is found that yellow LED with pre-wells exhibits a smaller blue shift, and a 2.

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Realization of efficient InGaN-based green light-emitting diodes (LEDs) is highly desirable in solid-state lighting industry. Here, we propose a stacked last quantum barrier (SLQB) GaN/AlN layer for green (∼550) LEDs grown on patterned sapphire substrate to improve the device performance. A green LED with a SLQB achieves a light output power (LOP) of 13 mW at 15 mA, which is 35% higher than that of LEDs with a conventional last quantum barrier (CLQB) GaN layer.

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Improving photothermal efficiency can reduce the melting threshold of metal nanowires. The photothermal efficiency of a polarized laser to Cu nanowires was investigated by numerical simulation and experiment. Our simulation results reveal that the photothermal efficiency of a polarized laser depends on the intensity and distribution area of surface plasmons excited by the laser.

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