Session Index

A power degradation mechanism in UV-C LEDs was discovered. After the LEDs were stressed for 250 hours, the output power dropped significantly under low current injection. Strong carrier leakage phenomenon was observed by I-V curve and C-V curve measurement. Electroluminescence spectrum suggested no apparent crystal quality degradation within the active region. Cross-sectional TEM showed that defect formation started at the p-GaN/EBL interface. Since EDS mapping showed that the nitrogen signal in p-GaN is weaker than that in its underlying layer, we inferred that p-GaN decomposition was activated by UV-C photons, and the emergence of nitrogen vacancies yielded strong leakage paths.

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We propose a novel subpixel rendering algorithm based for a GRGB LED panel, a transformation matrix that can display high-resolution images on low-resolution panels without losing details. Furthermore, we successfully exploit the characteristics of block-circulant matrix to reduce its computational load. The preliminary result shows that our algorithm achieves high image quality and less color distortion than the traditional DSD algorithm

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This study fabricated high-voltage, low-current DUV-LEDs by two devices connection. Due to a better current spreading and the reflective mirror effect enhanced in the high-voltage device, high-voltage devices present a higher dynamic resistance, emission output power, wall-plug efficiency, external quantum efficiency, and view angle than the single traditional device. The operating temperature exhibits a higher value in the traditional device in higher input power injection, then burns up at 5.5 W. The view angle presents 130 degrees at 100 mA input current.

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An AlGaInP-based red micro-light-emitting-diode (Micro-LED) array in 620nm wavelength is demonstrated in this paper. The micro-LED array with 10x10 pixels were fabricated and achieved enhancement with surface treatment. We measured and comparing the characteristics of micro-LED arrays with and without the (NH4)2Sx passivation.

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Solid state lighting sources have been widely used at this stage due to the high efficiency, long lifetime, compact size, short response time, Differing from the light-emitting diodes (LEDs), laser diodes (LDs) are mainly working through stimulated emission without serious efficiency droop when they exceed the threshold. In this study, the performance of cylindrical rod containing yellow phosphor for laser-driven white lighting was evaluated. At the meantime, a surrounding transparent layer around the phosphor containing cylindrical rod is also investigated to enhance the possibility of the blue light absorption by yellow phosphor in the phosphor containing cylindrical rod.

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The structure and properties of multilayer GaTe1-xSex are examined. The dominant monoclinic structure is obtained for x≤0.4, and dominant hexagonal structure is obtained for x≥0.5. The mixed-phase of GaTe1-xSex is verified by HRTEM and XRD. TRPL and area fluorecence lifetime mapping (AFLM) of the multilayer GaTe1-xSex indicates that the luminescence decay time constant increases with the selenium content, the decay time constant of the monoclinic phase is faster than the hexagonal phase. The results indicate that the M-GaTe1-xSex possesses higher polarized extinction ratio. GaTe1-xSex exhibits luminescence properties suitable for optoelectronic applications and photodetectors in the near infrared to visible range.

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Green quantum dot light-emitting diodes (QLEDs) comprised of inorganic/organic hybrid hole injection/transport layers with solution-process was reported. Molybdenum oxide (MoOx) was used as hole injection layer (HIL), Poly-TPD、PVK、TFB as hole transport layers (HTL) and magnesium doped zinc oxide nanoparticles (Mg0.1Zn0.9O NPs) served as electron transport layer (ETL) prepared by synthesis nanoparticles method for the fabrication of QLEDs were demonstrated. The maximum luminance (Lmax) of the fabricated green QLEDs can be up to 216,915 cd/m2 with current efficiency of about 25.03 cd/A.

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