  Platinum diselenide (PtSe2) is a newly discovered 2D material which is of
great interest for applications in electronics and catalysis. PtSe2 films were
synthesized by thermally-assisted selenization of predeposited platinum films
and scanning transmission electron microscopy revealed the crystal structure of
these films to be 1T. Raman scattering of these films was studied as a function
of film thickness, laser wavelength and laser polarization. Eg and A1g Raman
active modes were identified using polarization measurements in the Raman
setup. These modes were found to display a clear position and intensity
dependence with film thickness, for multiple excitation wavelengths, and their
peak positions agree with simulated phonon dispersion curves for PtSe2. These
results highlight the practicality of using Raman spectroscopy as a prime
characterization technique for newly-synthesized 2D materials.
