OT: white LEDs

Dave McGuire mcguire at neurotica.com
Mon Feb 22 21:25:49 CST 2010

On Feb 22, 2010, at 10:20 PM, Randy Dawson wrote:
> If you look at one in the microscope, it looks like an LED with  
> some sort of phosphor painted over the semiconductor.  Is that how  
> these things work, its really a high efficency IR LED, with a  
> phosphor doubler to bring the wavelength into visible?  Just  
> speculating...

   No, they're coated with a blend of phosphors designed to give  
"sorta" white light.  The native LED underneath the phosphor coating  
is usually blue.

   Remember, if you double the narrow-band output of some common IR  
LED output, you'll get some narrow-band visible output...more or less  
a single visible color.


Dave McGuire
Port Charlotte, FL

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