The two techniques are complementary and may be performed upon the same bench-top instrument as in both cases one is looking at the light that emminates from a sample (either from scattering or from luminescence emission).
The modern Raman microscope can often be used to obtain micro analysis and mapped images of a sample, using both techniques.
Some materials will however require a modified hardware arrangement as the two processes may occur in different regions of the optical spectrum.
For instance, Carbon nanotubes will often have the Raman analysis obtained in the visible region (300-800nm) whilst the PL exhibits emission in the NIR range, above 1000nm.
Similarly, III-V materials will generally have a PL emission in the 900-2000nm region, whilst the Raman may often be obtained using a green laser and the spectral range out to perhaps only 650nm.
For this reason new Raman/PL instruments have evolved which can combine two or more detectors, a CCD for work in the 200-1000nm range and NIR detectors such as InGaAs, which can cover out to 1600nm or 2000nm.
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