LED technology articles

industry7

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"
Applied Physics Letters, Volume 78, Issue 22, id. 3379 (2001).
Data are presented on high-power AlGaInN flip-chip light-emitting diodes (FCLEDs). The FCLED is ``flipped-over'' or inverted compared to conventional AlGaInN light-emitting diodes (LEDs), and light is extracted through the transparent sapphire substrate. This avoids light absorption from the semitransparent metal contact in conventional epitaxial-up designs. The power FCLED has a large emitting area (~0.70 mm2) and an optimized contacting scheme allowing high current (200-1000 mA, J~30-143 A/cm2) operation with low forward voltages (~2.8 V at 200 mA), and therefore higher power conversion (``wall-plug'') efficiencies. The improved extraction efficiency of the FCLED provides 1.6 times more light compared to top-emitting power LEDs and ten times more light than conventional small-area (~0.07 mm2) LEDs. FCLEDs in the blue wavelength regime (~435 nm peak) exhibit ~21% external quantum efficiency and ~20% wall-plug efficiency at 200 mA and with record light output powers of 400 mW at 1.0 A."

This article is from 2001 apparently, and an led like the one described here would be perfect for one of my projects. High output, high efficiency, high frequency deep blue/violet. That's exactly what I need. I've been having a hard time finding LEDs in that range. Most of the blue ones that I see are 470nm+ although I've found some excellent ones down to 450nm. Does anyone know a good source for 420nm-435nm?
 

tebore

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"
Applied Physics Letters, Volume 78, Issue 22, id. 3379 (2001).
Data are presented on high-power AlGaInN flip-chip light-emitting diodes (FCLEDs). The FCLED is ``flipped-over'' or inverted compared to conventional AlGaInN light-emitting diodes (LEDs), and light is extracted through the transparent sapphire substrate. This avoids light absorption from the semitransparent metal contact in conventional epitaxial-up designs. The power FCLED has a large emitting area (~0.70 mm2) and an optimized contacting scheme allowing high current (200-1000 mA, J~30-143 A/cm2) operation with low forward voltages (~2.8 V at 200 mA), and therefore higher power conversion (``wall-plug'') efficiencies. The improved extraction efficiency of the FCLED provides 1.6 times more light compared to top-emitting power LEDs and ten times more light than conventional small-area (~0.07 mm2) LEDs. FCLEDs in the blue wavelength regime (~435 nm peak) exhibit ~21% external quantum efficiency and ~20% wall-plug efficiency at 200 mA and with record light output powers of 400 mW at 1.0 A."

This article is from 2001 apparently, and an led like the one described here would be perfect for one of my projects. High output, high efficiency, high frequency deep blue/violet. That's exactly what I need. I've been having a hard time finding LEDs in that range. Most of the blue ones that I see are 470nm+ although I've found some excellent ones down to 450nm. Does anyone know a good source for 420nm-435nm?

The latest Luxeons (K2 and Rebel TFFC) are applying this Flip chip principle.
 
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