A new Raman spectrometer with options to go down to low temperatures of 4.2 K and high pressure up to 20 GPa has been installed recently. The spectrometer was calibrated using various standard reference materials e.g. silicon, diamond and Ge etc. A large number of samples both at room temperature and at low temperatures have been studied. We shall be reporting here Raman Spectroscopic studies of five technologically novel materials at room temperature namely GaN, Cu2ZnSnS4 (CZTS), Doped Lithium Niobate (LiNbO3), YVO4 [Eu+3, Sm+3] and finally Sb2Te3 . For low temperature studies, we have selected Sb2Te3 up to 77 K. We have analyzed the results from the theoretical estimation of optical phonons which are described by the irreducible representation of the crystal structures and then compared these with the experimental data. For low temperature studies, the temperature dependent Raman frequency shift has been studied. The systematic shifts have been explained in light of the thermal expansion and anharmonic phononphonon interactions. In both these studies [room & low temperatures], close agreements between the theoretically obtained data with the experimentally obtained Raman modes or shift are very encouraging.