James S
Flashlight Enthusiast
bluish white LED\'s due to failed phosphor?
Hi Folks,
In runtime testing some lights I've been making I've noticed interesting faults with some LED's phosphors. I've got a 2 LED light built into a AAA battery case and right now it has run down to the point where the light is useless, but you can quite clearly see the die when you look in them. I mixed LED's from 2 separate orders in this by accident. One has very good white light, and the other is much more bluish.
If I look closely at the white one the phosphor is smooth coating the whole die cup. There is a bluish square denoting the chip, but otherwise the phosphor is completely covering everything.
In the bluish one the phosphor has cracks in it letting out more of the blue light. It's like lightening bolts of blue shooting through the white. They are very pronounced.
Could bluish white LED's be caused more by failures in the phosphor coating process rather than just by different formulations and such?
-James
Hi Folks,
In runtime testing some lights I've been making I've noticed interesting faults with some LED's phosphors. I've got a 2 LED light built into a AAA battery case and right now it has run down to the point where the light is useless, but you can quite clearly see the die when you look in them. I mixed LED's from 2 separate orders in this by accident. One has very good white light, and the other is much more bluish.
If I look closely at the white one the phosphor is smooth coating the whole die cup. There is a bluish square denoting the chip, but otherwise the phosphor is completely covering everything.
In the bluish one the phosphor has cracks in it letting out more of the blue light. It's like lightening bolts of blue shooting through the white. They are very pronounced.
Could bluish white LED's be caused more by failures in the phosphor coating process rather than just by different formulations and such?
-James
