Our group and other researchers have already reported on the successful growth of high-quality ZnO NWs using a simple technique consisting in the oxidation of Zn metal films in ambient conditions [16–22]. The simplicity of the process, the low temperature required (close to 500°C), as well as the good quality of the obtained NWs make this method attractive for future nanodevice applications. It is noteworthy that many reports on the optical properties of ZnO nanorods and NWs point out to the apparition
of a deep-level emission (DLE) band in the visible, together with the near-band edge emission (NBE) in the UV. In this sense, to change their optical properties, buy SC79 several studies on https://www.selleckchem.com/products/sbi-0206965.html emission tailoring of ZnO NWs exposed to an irradiation source have already been developed [23–25] but with contradictory outcomes. In particular, with regard to the optical response, Krishna and co-workers reported the occurrence of several bands in the visible region which were identified in the PL spectra of 15-keV energy Ar+-irradiated thin films. They indicated a strong detraction of the visible signal with selleck products respect to the UV emission
, and similar optical results were confirmed by Liao and co-authors in the case of 5 to 10 kV Ti-implanted ZnO NWs . Besides the modification of the UV/visible intensity ratio, UV signal blueshift was found by Panigrahy for 2- to 5-keV Ar+-irradiated ZnO nanorods . The UV blueshift was also detected in the cathodoluminescence (CL) spectra of ZnO NWs irradiated with 30-keV Ti+ ions. Nevertheless, in this case, the visible emission did not suffered changes with the implantation doses , contrary to the behavior observed by Wang et al.  who reported a complete disappearance of the visible
emission from ZnO NWs irradiated with 2-keV H+ ions. Hence, the modification of the luminescence properties of ZnO after irradiation experiments is still not clearly understood and, even less, after low energy irradiation experiments. In any case, it would be desired Palbociclib purchase to tailor the ZnO NW emission by minimizing the visible emission and therefore improving the UV luminescence. This would be particularly important in the case of cost-effective growth procedures, for which the obtained ZnO NWs could present some important emissions in this spectral range. In this work, we present the results of exposing ZnO NWs to a low-energy (≤2 kV) Ar+ ion irradiation. These experiments require a relatively simple experimental setup where only a small high-vacuum chamber and an ion gun are needed. Our experimental results show that the irradiation gives rise to an increase of the UV emission with respect to the visible one. We base the explanation of these effects on the structural analysis performed on individual NWs.