Photoluminescence investigation of crystalline undoped ZnO nanostructures constructed by RF sputtering

By using a Radio Frequency (RF) sputtering technique, Zn and ZnO nanostructures were fabricated on different substrates. ZnO nonorganics were synthesized on glass substrates, and Zn nanowires, ZnO nanoparticles and ZnO nanorods were synthesized on silicon substrates. The obtained ZnO nanograins ranging from 30 to 100 nm in size showed an almost single-crystalline structure. The agglomerated ZnO nanoparticles and ZnO nanorods exhibited a polycrystalline structure. The size of agglomerated nanoparticles is in the range of 40–150 nm, and the nanorods have a diameter of about 60 nm and a length of about 650 nm. There are four peaks in the range of 400–570 nm of the photoluminescence (PL) spectra, at room temperature. The strong peaks in PL of these samples are related to green and violet emissions. The PL spectra of the grown samples indicate that the nanorods fabricated by reactive sputtering can be a good choice for use in optoelectronic devices, such as diode lasers and LEDs.