In this paper, the UV Raman spectra of a large number of saturated and alkyl-substituted monocyclic, bicyclic and polycyclic aromatic hydrocarbons are obtained at 220 and 233 nm excitation wavelengths. Also included are nitrogen- and sulphur-containing hydrocarbons. The spectra obtained are fluorescence free, even for such highly fluorescent compounds as perylene, consistent with earlier reports of UV Raman spectra of hydrocarbons. The hydrocarbon UV Raman spectra exhibit greatly improved signal-to-noise ratio when in the neat liquid or solution state compared with the neat solid state, suggesting that some surface degradation occurs under the conditions used here. Assignments are given for most of the bands and clear marker bands for the different classes of hydrocarbons are readily observable, although their relative intensities vary greatly. These results are discussed in the context of structure and symmetry to develop a consistent, molecular-based model of vibrational group frequencies.

Raman and resonance Raman spectroscopy with ultraviolet excitation were performed on several sample types of oilsands-derived bitumen, highly heterogeneous mixtures of hydrocarbons, and commercial gasoline samples. Only excitation wavelengths below ∼240 nm successfully yielded fluorescence-free Raman spectra on all of the samples tested. The spectra were surprisingly simple in the 800–1800 cm−1 region, with most of the samples yielding spectra containing only 2 bands. The results presented here tentatively suggest that ultraviolet (UV) Raman spectroscopy in the “fingerprint” spectral regions will be useful for the qualitative identification of saturate, mono-, bi-, tri-, and polycyclic aromatic hydrocarbons. Tentative marker bands for total aromatic, saturate, mono-, and bicyclic (or higher) aromatic hydrocarbons are clearly observed at ∼1600, <900, 1036, and ∼1380 cm−1, respectively. Observed relative intensities vary with the excitation wavelength from 220 to 234 nm, suggesting that some selectivity is achievable by wavelength tuning. Preliminary investigations of commercial gasoline samples indicate that UV Raman spectroscopy can be used for refinery/vendor identification of unknown gasoline samples.

We have performed an analysis on three hydrogenated nanocrystalline silicon (nc-Si:H) based solar cells. In order to determine the impact that impurities play in shaping the material properties, the XRD and Raman spectra corresponding to all three samples were measured. The XRD results, which displayed a number of crystalline silicon-based peaks, were used in order to approximate the mean crystallite sizes through Scherrer's equation. Through a peak decomposition process, the Raman results were used to estimate the corresponding crystalline volume fraction. It was noted that small crystallite sizes appear to favor larger crystalline volume fractions. This dependence seems to be related to the oxygen impurity concentration level within the intrinsic nc-Si:H layers.

Raman and resonance Raman spectroscopies were used to characterize industrial metal-refining solutions containing nitrogen, sulfur, and Ni, Co, Zn, and Cu ammine complex species. To identify the species present in these solutions, we also recorded Raman spectra of model compounds in similar matrices. The results indicate that clearly resolved diagnostic bands in the Raman spectrum can be used to identify and discriminate free ammonia, metal-bound ammonia, sulfate, sulfamate, and metal species in industrially relevant plant solutions. We roughly estimate that Raman can determine cobalt at the 0.3 g Co/L level, nickel at the ∼5 g Ni/L level, and copper at the 2–3 g Cu/L level in these solutions. Also, sulfate and sulfamate can be detected at the 1 g/L level with Raman spectroscopy. Finally, the Raman spectrum can be used to determine bound ammonia with detection limits of about 20 g/L. The detection of free ammonia depends on the concentration ratio of free to bound ammonia because of their overlapping vibrational bands and the weaker intensity of free ammonia Raman scattering.