نتایج جستجو برای: uv leds
تعداد نتایج: 74565 فیلتر نتایج به سال:
Phosphor‐converted white light emitting diodes (pc‐LEDs) are being used as a source of artificial lighting. One the main goals lighting is to make objects/images look natural — they under sunlight. The ability accurately render color an object gauged by rendering index (CRI) and conventional pc‐LED has average CRI—CRI R ~ 80 which not suitable for In order fabricate pc‐LEDs applications, all CR...
AlGaN-based ultraviolet-A light-emitting diodes (UVA LEDs) inevitably suffer from current crowding effects at high injection levels due to their lateral device structure, resulting in non-uniform light emission and overheating. In N-polar UV LEDs, the problem is further exacerbated by increased hole efficiency, leading aggravated leakage, which limits performance. An n-AlGaN/AlInGaN/AlGaN struc...
We report on the reliability of commercial UV-C (UltraViolet-C) LEDs (Light Emitting Diodes) subjected to constant current stress. Electrical, optical and spectral analysis was carried out with an emission peak 275 nm a nominal power 12 mW at 100 mA. Degradation tests were maximum rated current, double three times maximum. The LED lifetime found be inversely proportional third stress density, i...
Fluorescence microscopy requires high photon-flux densities in the specimen plane. These intensities are only achieved by lasers, arc lamps, and, most recently, light-emitting diodes (LEDs). Lasers and LEDs, however, are restricted to a limited number of wavelength regions, whereas with arc lamps it is possible to select arbitrary wavelengths and wavelength regions. Moreover, the lower cost of ...
High internal efficiency and high temperature stability ultraviolet (UV) light-emitting diodes (LEDs) at 308 nm were achieved using high density (2.5 × 10(9) cm(-2)) GaN/AlN quantum dots (QDs) grown by MOVPE. Photoluminescence shows the characteristic behaviors of QDs: nearly constant linewidth and emission energy, and linear dependence of the intensity with varying excitation power. More signi...
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