Decoration of ZnO needles with nanoripples using gas cluster ion bombardment
Introduction
Self-assembled surface nanostructures formation has a great interest for bio-sensors, surface plasmon resonance, catalysis, field emission, gas sensing, and other applications where morphologically developed surface is necessary. For the first time formation of the self-assembled nanostructures (nanoripples) on the surface by off-normal monoatomic ion irradiation was studied by Navez et al. [1]. A theoretical background of the nanoripple formation was given by Bradley and Harper on the base of the Sigmund's sputtering theory [2]. However, not only monoatomic ion beam is capable of surface nanostructures formation. Recently it has been demonstrated that off-normal gas cluster ion irradiation also can produce nanostructures on the solid surface [3], [4], [5], [6], [7]. Due to a big size of the gas cluster (about 1000 atoms) the energy per atom is very low, which results in shallower penetration of the cluster atoms into the substrate (a few nm) and, as a consequence, in low damage of the surface layer as compared with the monoatomic beam [8]. All previous researches employing the gas cluster ion beam were devoted to formation of the nanostructures on the planar substrates. In this work we demonstrate fabrication of the nanostructures on the surface of ZnO needles. The results obtained in this study are of interest in applications of ZnO nanostructures for gas sensing, solar cells, field emitters, and so on, where developed surface morphology is required.
Section snippets
Experimental
To study the process of nanoripple formation on the nanostructured samples, ZnO needles were grown using the vapor phase deposition technique. An alumina boat with Zn granules (purity 99.9%) was placed into an alumina tube of a furnace. A 10 × 10 mm highly p-type doped Si 〈1 0 0〉 substrates (HF-Kejing Materials Technology Co., Ltd.) were mounted above the alumina boat. The tube was vacuumed by a mechanical pump to a pressure of 10 Pa. Then, an oxygen was introduced into the alumina tube at a
Results and discussion
In Fig. 2 (a) as-grown ZnO micro sized needles are shown. Fig. 2 (b,c) demonstrate effect of the Ar cluster bombardment on the needle surface. 10 and 15 kV bombardments result in formation of fine nanoripples with the wavelengths of 83 ± 15 and 93 ± 15 nm, respectively. A small increase of the ripple wavelength along with increasing accelerating voltage can be explained as follows. It is obvious that at higher cluster energy the sputtering yield of a target material and, consequently, amount of
Conclusions
The gas cluster bombardment has demonstrated capability of the nanoripple formation on the surface of the ZnO needles. Nanoripples with the wavelength of about 90 nm have been fabricated by the Ar1000+ cluster ions accelerated by a voltage of 10 and 15 kV and fluence of 3 × 1016 cluster/cm2. The influence of the accelerating voltage and the size of the irradiated area on the ripple formation have been studied. The ripples formed at higher accelerating voltage on the thinner needles demonstrate
CRediT authorship contribution statement
Vasiliy Pelenovich: Conceptualization, Methodology, Investigation. Xiaomei Zeng: Data curation, Writing - original draft. Rakhim Rakhimov: Validation, Resources. Wenbin Zuo: Writing - review & editing. Canxin Tian: Visualization, Funding acquisition. Dejun Fu: Funding acquisition. Bing Yang: Project administration.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements
This work was supported by the National Natural Science Foundation of China (11875210), the International Cooperation Program of Guangdong province science and technology plan project (2018A050506082), China Postdoctoral Science Foundation under grant 2019M652687, and Talent project of Lingnan Normal University (ZL1931).
References (11)
- et al.
Cluster size dependence of surface morphology after gas cluster ion bombardments
Nucl. Instrum. Methods B
(2008) - et al.
Cluster ion beam assisted fabrication of metallic nanostructures for plasmonic applications
Nucl. Instrum. Methods B
(2016) - et al.
Gold nano-ripple structure with potential for bio molecular sensing applications
Sensing Bio-Sensing Res.
(2016) - et al.
Materials processing by gas cluster ion beams
Mater. Sci. Eng. R
(2001) - et al.
Surface morphology and sputtering yield of SiO2 with oblique-incidence gas cluster ion beam
Nucl. Instrum. Methods B
(2013)