Swift heavy ion induced optical and structural modifications in RF sputtered nanocrystalline ZnO thin film

In the present study, 100 MeV Ag7+ ion beam-induced structural and optical modifications of nanocrystalline ZnO thin films are investigated. The nanocrystalline ZnO thin films are grown using radio frequency magnetron sputtering and irradiated at fluences of 3 x 10(12), 1 x 10(13) and 3 x 10(13) ions/cm(2). The incident swift heavy ions induced change in the crystallinity together with the preferential growth of crystallite size along the c axis (002) orientation. The average crystallite size is found to be increased from 10.8 +/- 0.7 to 20.5 +/- 0.3 nm with increasing the ion fluence. The Atomic force microscopy analysis confirms the variation in the surface roughness by varying the incident ion fluences. The UV-visible spectroscopy shows the decrement in transmittance of the film with ion irradiation. The micro-Raman spectra of ZnO thin films are investigated to observe ion-induced modifications which support the increased lattice defects with higher fluence. The variation in crystallinity indicates that ZnO-based devices can be used in piezoelectric transduction mechanism.