Dopant induced local vibrational modes and Fano scattering in Ag doped ZnO microrods.

We discussed the influence of Ag doping on the crystallite size of ZnO and enhanced Raman spectroscopy properties. We reported optical and vibrational properties of Ag-doped ZnO microrods which have been prepared through reflux method. Dopant induced shift and asymmetric broadening of Raman modes have been discussed. In Raman spectra, silver doping induces a lower wavenumber shift in E mode. Moreover, the appearance of some additional peaks after Ag-doping were successfully studied and the doping is confirmed by the local vibration modes obtained at 230 and 390cm. Effect of doping is studied by calculating the crystallite size and we discussed the variations in full width half maximum (FWHM), phonon lifetime with respect to varying crystallite size. Phonon lifetime decreases with increasing Ag concentration. The asymmetric broadening in Raman modes E and E with the addition of Ag are analysed with Fano fitting.