From Raman: E1(transversal) 437 cm-1 A1 (transversal) 380 cm-1 ; A1 (longitudinal) 583 cm-1, A1 (longitudinal). A1 and E1 are active also in FTIR. Clusters of zinc oxide should have a bandgap major of the 3.3 eV. By means of Tauc plot method you can obtain this information from UV-VIS transmittance and reflectance measurements.