Will there be a sea change in white LEDs?

LEDninja

Flashlight Enthusiast
Joined
Jun 15, 2005
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One of the problems with white LEDs is the heat generated by the phosphor. This heat has no where to go. The LED die behind is hotter.

So phosphor tends to burn. LEDs turning blue before they die. Tint shift over time. This last is critical as Energy Star LED retrofit bulbs must not have a tint change over 35,000 hours.



At the LED level Cree had released the XPE-HEV. The phosphor has an alternate way of dissipating heat via the LED dome.

http://www.candlepowerforums.com/vb/...d.php?t=304330

At the light bulb level The phosphor is on the dome of the bulb itself, even further away from the LED die. Only blue LEDs needed.

Cree demonstration A-19 bulb.

http://news.cnet.com/8301-11128_3-20...=2547-1_3-0-20

Philips 12W Endura.

http://www.candlepowerforums.com/vb/...d.php?t=308557

Philips 8W AmbientLED.

http://www.candlepowerforums.com/vb/...61#post3685961



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Meanwhile the TV and monitor people are moving away from cold cathode tubes to LEDs for backlighting. LCDs only need RGB (except Sharp which uses RYGB). They do not need the full spectrum of white LEDs. Quantum dot based phosphors or improved R,G,B LEDs would be more efficient.



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So would current white LEDs as we know it go the way of the DoDo bird?
 
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