Raman signal of black matte object
The comments pretty much sum up whats going on, but here is a more in-depth explanation to clear up any confusion for the OP.
There is a lot more behind this but here is the (very) basic principle:
Raman spectroscopy uses monochromatic light to excite molecules. These photons interact inelastically with the molecule (i.e. they gain or lose kinetic energy) and are then scattered. Some detector analyzes the scattered light and determines vibrational energy levels by calculating how much kinetic energy the photon has gained/lost which corresponds to the difference in energy of the vibrational modes.
When a black object is hit with a laser, the photons are absorbed. The absorbed energy is released as heat (This is why black cars are significantly hotter inside than white cars when left in the sun). Maybe some scattering does occur, but who knows if it is detectable. There are some articles on trying to determine the Raman spectra of black objects [Here is one].
Do some research; look at the Journal of Raman Spectroscopy if it peaks your curiosity. I'm not saying it is impossible, but it might require a lot of effort and understanding of the fundamental principles of this technique.