2
$\begingroup$

As far as I understand, white LEDs and CFLs both use phosphor mixtures to convert part of their primary emission spectrum to longer wavelengths. What puzzles me is the difference in the resulting spectra.

I would expect these to be similar as the spectra are mainly phosphor dependent, but in reality they differ significantly between both lamp types:

Color spectra of different lamps

I understand the stronger blue peak in the LED spectrum, what is just the primary emission shining through the phosphor.

But the CFL lamps show characteristic peaks, as I know them from typical X-Ray phosphors like GOS:Tb - and the LED spectrum is much smoother.

The question, straight to the point: why are these spectra so different?

And in more detail: Does this mean, that LEDs can use different phosphors than CFL lamps? If yes, why are these not available for CFL - are they too instable in contact with the plasma? Why do these phosphors have broader emission peaks? Are these organic compounds?

Thanks in advance.

Improve this question
$\endgroup$
1
  • $\begingroup$ Much of the structure in the CFL is the mercury emission lines. Since they appear across the visible range, your eye does a good job of seeing them as mainly white, the phosphor's main job is to adjust the colors a bit. The LED has one emission line, and needs a variety of phosphors to make something that looks white to the human eyeball. For the CFL, no need to smooth things out - your eye isn't a spectrometer. $\endgroup$ – Jon Custer Nov 6 '17 at 21:23

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.