Evidence of laser induced decomposition of triaminotrinitrobenzene from surface enhanced Raman spectroscopy

It is observed that the focused 632 nm laser of the confocal micro-Raman spectrometer decomposes triaminotrinitrobenzene (TATB). The temperature generated in the laser spot determined by measuring the ratio of the intensities of the anti-Stokes to Stokes spectra is too low to cause thermal decomposition. The observed decomposition is suggested to be a result of laser induced electronic excitation. The decomposition is even more severe when measured by surface enhanced Raman spectroscopy (SERS) where it results in a highly defected graphite structure. A gold coated silicon substrate having an array of pyramidal shaped holes is used to obtain surface enhanced Raman spectra of TATB deposited on the substrate as a 10^?3 molar solution of toluene.