lazerlover
Newly Enlightened
- Joined
- Jul 6, 2007
- Messages
- 35
Does anyone have a figure for this, for normal high powered white led's like cree or luxeon? I am not looking for luminous efficiency.
The phosphors are actually not far off 100% theoretical efficency. Remember that for phosphor conversion there are inherent Stokes losses (i.e. Stokes shift ) which are larger the further apart the absorbed and reemitted wavelengths are (this is why phosphors which produce more red are less efficient). For white LEDs made with blue emitters and YAG phosphors the maximum theoretical phosphor conversion efficiency is around 82%. Actual phosphor conversion efficiency is somewhere in the high 70s.How efficient are the cool, neutral and warm white phosphors after all?