Polarized and non?polarized Raman spectroscopy of ZnO crystals: Method for determination of crystal growth and crystal plane orientation for nanomaterials

Analysis and determination of crystal orientation exposed surface facets remain a challenge in nanomaterial science. In this work, we show that polarized non-polarized Raman spectroscopy can be useful tools to determine plane conveniently applied spatial dimensions limited only by the diffraction limit excitation laser. The methodology is exemplified for wurtzite structured ZnO. Three different facets, (0001), (1 00), (11 0), ZnO are investigated with angle-resolved spectroscopy. polarization direction dependences main peaks characterized related experimental vibrational modes lattice corroborated density functional theory (DFT) calculations using two hybrid functionals. By exploiting symmetry differences intensity optically activated phonons, simple model derived determining relation between polar non-polar orientation. results generalized allow peak ratio analysis light source, making it compatible mapping, as well include critical discussion on ability nanodimensional equivalent models other nanomaterials. As approach allows use sources, near-field excitations local plasmons an extension utilized planes much smaller than limit.