in photoluminescence, the source of excitation and the wavelength with which we exite changes, I would like to know what is best for my material knowing that it is a semiconductor of ZnS powder (UV lamp, visible lamp, laser or xenon lamp ..)
Hi,
ZnS, if my memory serves me well, it is use in Cathode Ray Tubes as a screen to observe impinging electrons on the screen. But i guess that ZnS is doped with another metals to create an intermediate bands to get the phosphorescence effect. The glow that is produce lies in the green region of the electromagnetic spectrum. On the similar lines, the excitation light in your case (if pure ZnS) should be 300nm or below (characterise your sample in UV-VIS to know the exact wavelength).
Regards
It depends on what you want to observe. If your aim is to observe photoluminescence due to band-to-band recombination, then use light with an energy higher than the ZnS bandgap (e.g., UV). A (UV) lamp or laser could be used, provided they emit enough power to induce a luminescence signal strong enough so that it can be detected by your detection system. A UV laser is always better if you need a high monochromatic power, but it is more expensive.
There are not so expensive and rather powerful UV LED with 360 nm emitting wavelength. It is rather close to cubic ZnS bandgap energy
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