- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Size effect on optical performance of blue light-emitting diodes
摘要： In this paper, size effects on optical performance of blue light-emitting diodes (LEDs) are investigated. The essential physical mechanism is studied by fabricating LEDs with various sizes of the active area and testing optical characteristics. It is found that micro-LEDs have better light extracting efficiency and thermal dissipation compared with broad-area LEDs, which is likely due to the small ratio of perimeter and active area. Furthermore, micro-LEDs are more beneficial for displays due to the stable wavelength under the low pulse width modulation (PWM) current density.
关键词： size dependence,micro-LED,strain relaxation,light extract efficiency
更新于2025-09-19 17:13:59
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Large Wavelength Response to Pressure Enabled in InGaN/GaN Microcrystal LEDs with 3D Architectures
摘要： Optical detection of pressure has the advantage of direct and dynamic indication of the pressure distribution with a high spatial resolution. In this study, microcrystal (μ-crystal) light-emitting diodes (LEDs) that can exhibit an unprecedented large wavelength response to pressure are demonstrated. As a key strategy, three-dimensional InGaN/GaN μ-crystals are engineered to have a hollow core and multiple facets with different multiple quantum well (MQW) structures. The unique structure allows pressure-sensitive modulation of the dominantly emitting MQWs, resulting in an anomalously large change of ~50 nm in the ultimate emission wavelength under an external stress of 8 MPa. The underlying mechanism is elucidated via finite-element analysis of the strain development in the μ-crystals and the corresponding piezo-potentials. The results of the study suggest a new capability for dynamic color mapping of the pressure distribution with a high spatial resolution.
关键词： InGaN/GaN microcrystal,micro-LED,optical sensor,wavelength change,pressure sensor
更新于2025-09-19 17:13:59
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16.5: <i>Invited Paper:</i> Manufacturing Solutions for Micro‐LED Displays
摘要： The aggressive performance and yield requirements for micro-LED displays while adhering to strict cost targets create many challenges for the manufacturing of such displays. In this talk, we will present advances in MOVCD epitaxy and mass transfer to enable micro-LED display adoption for signage and consumer applications.
关键词： Epitaxial growth,Micro-LED displays,Mass transfer
更新于2025-09-19 17:13:59
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Single-Cell Optogenetic Control of Calcium Signaling with a High-Density Micro-LED Array
摘要： Precise optogenetic control, ideally down to single cells in dense cell populations, is essential in understanding the heterogeneity of cell networks. Devices with such capability, if built in a chip scale, will advance optogenetic studies at cellular levels in a variety of experimental settings. Here we demonstrate optogenetic control of intracellular Ca2+ dynamics at the single cell level using a 16-μm pitched micro-LED array that features high brightness, small spot size, fast response, and low voltage operation. Individual LED pixels are able to reliably trigger intracellular Ca2+ transients, confirmed by fluorescence microscopy, control experiments, and cross-checked by two genetically-coded Ca2+ indicators. Importantly, our array can optogenetically address individual cells that are sub-10 μm apart in densely packed cell populations. These results suggest the possible use of the micro-LED array towards a lab-on-a-chip for single-cell optogenetics, which may allow for pharmaceutical screening and fundamental studies on a variety of cell networks.
关键词： optogenetic control,lab-on-a-chip,calcium signaling,micro-LED array,single-cell
更新于2025-09-19 17:13:59
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Research on Luminance Distributions of Chip-On-Board Light-Emitting Diodes
摘要： Chip-On-Board Light-Emitting Diodes (COB LED) are increasingly more common. Their development in recent years has directly contributed to increasing the power of LED sources, whilst simultaneously increasing the luminous ?ux from the entire COB. Consequently, it has led to new developments in some applications. Information regarding the size of the light source luminous surface and luminance distribution on its surface is critical for a designer whilst designing optical systems. The purpose of this conducted research was to establish to what extent luminance distribution is even on the examined COB LEDs. In order to verify luminance distributions on an LED surface, direct measurements with a matrix luminance measuring device were made. As a result of the research, it has been observed that luminance distribution is not even, and in many cases luminance maximum does not fall in the geometric center of the luminous surface, which was initially expected. So, it has been concluded that while designing optical systems for COB LEDs, irregular luminance distribution on their surface needs to be considered.
关键词： LED,luminance distribution,COB,lighting technology,Chip-On-Board,COB LED,light-emitting diodes,micro LED
更新于2025-09-16 10:30:52
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P‐9.3: The representation of monochromatic blue Micro‐LED arrays with 1984 ppi
摘要： Blue InGaN/GaN Micro-LED arrays based on silicon and sapphire substrates were fabricated respectively. The LED chips with 12.8 μm pixel pitch share a common n contactor in a 960*540 LED array. The driving current for a single LED chip with 8 μm mesa reaches as large as 20 mA, which indicates its current density is much larger than that of LEDs even in high power lighting application. Meanwhile, the reverse leakage current of a single 8μm size LED chip under -5V bias is below 10 pA, which falls within the range of a normal leakage current level for InGaN/GaN LED. The heat pressing bonding process between LED array and test backplane was also carried out for I-V-L test. The test results of LED arrays were presented.
关键词： Micro display,Flip-chip bonding,Micro-LED
更新于2025-09-12 10:27:22
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P‐16.1: Study of Active Matrix Circuits Design for Micro‐LED displays and Visible Light Communications
摘要： Because Micro-LED is the current-driven device, there are usually two types of the matrix driving circuit, passive matrix driving circuit, and active matrix driving circuit. Comparing these two driving circuits, the active driving circuit can achieve better brightness uniformity, higher contrast and lower contrast. Therefore, most of Micro-LEDs use active matrix driving circuit. In this paper, a study of active matrix circuit design for Micro- LED displays and beyond display applications such as visible light communication will be reported. The pixel circuit integrates two parts of VLC together, the emitter and the receiver. When the LED is on, it can work as the emitter of VLC. When the LED is off, the photodetector can work as the receiver of the VLC. This can offer more varieties of the application, such as face-to-face data transmission, under-screen fingerprint identification and so on.
关键词： pixel circuit,Micro-LED display,visible light communication
更新于2025-09-12 10:27:22
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Optimization of the optical structure of thin direct-lit LED backlights for LCD applications by using micro-LEDs
摘要： The optimized optical structure of the micro-LED-based direct-lit backlight was investigated through optical simulation. The backlight consisted of only one diffuser plate and an array of micro-LEDs with a reflection film positioned on the bottom of the backlight. An additional reflector was put on top of each micro-LED to prevent the formation of bright spots. Under several number density conditions of the microbeads in the diffuser plate, stable regions were found on the gap-pitch plot, where a high Mura index of ～ 1 was secured. The bead density needed to be small (around 104 mm?3) to maintain above 60% transmittance, because the transmittance of the backlight was significantly reduced at higher bead densities. Under the 104 mm?3 bead density condition, the gap can be reduced to 1.5 mm at a 3 mm pitch. The gap can be further reduced if additional optical films, such as a diffuser sheet, a prism film, and a reflective polarizer, will be adopted in the backlight. This work demonstrated that micro-LEDs are ideal light sources for realizing a thin direct-lit backlight for LCD applications.
关键词： simulation,LCD,Micro-LED,backlight,direct-lit
更新于2025-09-12 10:27:22
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A monolithically integrated micro-LED display based on GaN-on-Silicon substrate
摘要： A monolithic micro-light-emitting-diode (LED) display technology was proposed using a gallium-nitride-on-silicon substrate. An active matrix (AM) display was realized by interconnecting nitride-based LEDs as display pixels with silicon (Si) thin-film-transistors (TFTs) as driving circuitries. Metal-oxide semiconductor TFTs were fabricated on Si surface which had been exposed after the dry etching of LED epitaxial layer. The mobility and sub-threshold slope were measured as 354.3 cm2/Vs and 0.64 V/dec, respectively. A 150 pixel-per-inch 0.6-inch monolithic display was demonstrated with a 60 x 60 pixel-array AM display by an integration technology on the same substrate.
关键词： micro-LED,monolithic integration,active matrix display,GaN-on-Silicon
更新于2025-09-12 10:27:22
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P‐9.10: Fabrication of micro scale and ultra‐thin LEDs for micro‐LED display applications
摘要： Presented here are the fabrication techniques for preparing micro scale and ultra-thin LEDs for micro-LED display applications. Lateral dimension less than 100μm and thickness of 5μm LED devices are fabrication and the preparing micro LEDs are transferred from the original growth substrate to the glass substrate successfully. The optoelectronic performance of micro scale and ultra-thin LEDs transferred on to the glass substrate as good as that of on the original growth substrate has achieved.
关键词： Micro LED Display,Micro LED,transfer
更新于2025-09-11 14:15:04