Optimisation on the Growth and Alignment of ZnO Nanorods

Abstract:

Synthesis of aligned ZnO nanorods (NRs) is important for electronic and optoelectronic devices. In this work we demonstrate the growth of ZnO nanorods by co-precipitation method using zinc nitrate and hexamine precursors. The samples were characterized by X-ray diffraction analysis, Scanning electron microscopy and Raman spectroscopy. On introducing the seeded substrate into the growth solution, the seeds offer nucleation sites for one-dimensional growth of ZnO nanorods. ZnO nanorod arrays grown on the successive ionic layer adsorption and reaction (SILAR) seed layer found to be irregular and non-uniform due to the etching of the seed substrate by growth solution. However, dip-coated seed substrate yielded uniform growth of ZnO nanostructures. ZnO nanostructures with flower-like morphology were obtained for pH of 9. On reducing the pH of the growth solution the flower morphology transformed into rod-like morphology with rod diameter of 200nm. On reducing the pH to 3 the diameter of the nanorods is decreased to 20 to 25nm. On reducing the precursor concentration the faceted morphology of the nanorods changed into needle-like shape (with sharp tips) along with reduction in diameter (about 20nm). The growth of uniform and vertically aligned ZnO nanorods is observed in dip-coated seed substrate with 5 pH. The results indicate that the diameter of ZnO nanorod array could be controlled by varying the precursor concentration.

• Periodical: Advanced Materials Research (Volume 584)
• Pages: 319-323
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.584.319
• Online since: October 2012
• Authors: Kugalur Shanmugam Ranjith, Ramanathaswamy Pandian, Gomathi Natarajan, Mohammed Kamruddin, Ramasamy Thangavelu Rajendrakumar
• Keywords: Nucleation, Vertical Nanorods, ZnO Buffer Layer, ZnO Nanorod Array

References

[1] Hirokazu Asahara, Daiju Takamizu et al, Light-Emitting Diode Based on ZnO by Plasma-Enhanced Metal–Organic Chemical Vapor Deposition Employing Microwave Excited Plasma, Japanese Journal of Applied Physics. 49 (2010) 04DG14 1-4.

DOI: 10.1143/jjap.49.04dg14

[2] Hui Pan, Yanwu Zhu, Han Sun et al, Electroluminescence and field emission of Mg-doped ZnO tetrapods Nanotechnology. 17 (2006) 5096–5100.

DOI: 10.1088/0957-4484/17/20/009

[3] Chin-Hsien Hung, Wha-Tzong Whang, A novel low-temperature growth and characterization of single crystal ZnO nanorods, Materials Chemistry and Physics. 82 (2003) 705-710.

DOI: 10.1016/s0254-0584(03)00331-6

[4] Antaryami Mohanta and Raj K. Thareja, Photoluminescence study of ZnO nanowires grown by thermal evaporation on pulsed laser deposited ZnO buffer layer, J. Appl. Phys. 104 (2008) 044906 1-6.

DOI: 10.1063/1.2969908

[5] Gong Jiangfeng, Dou Zhaoming, Ding Qingping, Xu Yuan, and Zhu Weihua, Controlled Synthesis of ZnO Nanostructures by Electrodeposition Method, Journal of Nanomaterials. 2010 (2010) 740628 1-6.

DOI: 10.1155/2010/740628

[6] Li Cao, Bingsuo Zou, Chaorong Li et al, Laser emission of low-threshold excitation from ZnO nanowires, Euro phys. Lett. 68 (2004) 740–745.

DOI: 10.1209/epl/i2004-10264-8

[7] S. T. Tan, X. W. Sun, and X. W. Sun, Ultraviolet and visible electroluminescence from n-ZnOSi Ox (n,p)-Si heterostructured light-emitting diodes, Applied Physics Letters. 93 (2008) 013506 1-3.

DOI: 10.1063/1.2957465

[8] Guozhen Shen, Yoshio Bando, Baodan Liu, Dmitri Golberg, and Cheol-Jin Lee, Characterization and Field-Emission Properties of Vertically Aligned ZnO Nanonails and Nanopencils Fabricated by a Modified Thermal-Evaporation Process, Adv. Funct. Mater. 16 (2006) 410-416.

DOI: 10.1002/adfm.200500571

[9] Ye Sun, Gareth M. Fuge, Michael N.R. Ashfold, Growth of aligned ZnO nanorod arrays by catalyst-free pulsed laser deposition methods, Chemical Physics Letters. 396 (2004) 21–26.

DOI: 10.1016/j.cplett.2004.07.110

[10] Jong Seok Jeong, Jeong Yong Lee, Jung Hee Cho et al, Growth behavior of well-aligned ZnO nanowires on a Si substrate at low temperature and their optical properties Nanotechnology, 16 (2005) 2455–2461.

DOI: 10.1088/0957-4484/16/10/078

[11] Ming Wang, Chang-Hui Ye, Ye Zhang et al, Synthesis of well-aligned ZnO nanorod arrays with high optical property via a low-temperature solution method, Journal of Crystal Growth. 291 (2006) 334–339.

DOI: 10.1016/j.jcrysgro.2006.03.033

[12] Xiang Liu, Xiaohua Wu, Hui Cao, and R. P. H. Chang, Growth mechanism and properties of ZnO nanorods synthesized by plasma-enhanced chemical vapor deposition J. Appl. Phys. 95 (2004) 1646440 1-7.

DOI: 10.1063/1.1646440

[13] Chen-Hao Ku and Jih-Jen Wu, Aqueous Solution Route to High-Aspect-Ratio Zinc Oxide Nanostructures on Indium Tin Oxide SubstratesJ. Phys. Chem. B. 110 (2006) 12981-12985.

DOI: 10.1021/jp061458b

[14] Juan Zhao, Zheng-Guo Jin, Tao Li, Xiao-Xin Liu, Nucleation and growth of ZnO nanorods on the ZnO-coated seed surface by solution chemical method, Journal of the European Ceramic Society. 26 (2006) 2769–2775.

DOI: 10.1016/j.jeurceramsoc.2005.07.062