Significant Effect on Annealing Temperature and Enhancement on Structural, Optical and Electrical Properties of Zinc Oxide Nanowires

S Paiman, T Hui Ling, M. Husham, Suresh Sagadevan
2020 Results in Physics  
This paper focused on the growth of zinc oxide nanowires on unannealed and annealed indium tin oxide-coated-coated glass substrates on the structural, optical, and electrical properties towards surface acoustic wave (SAW) piezoelectric nanodevices. Zinc oxide nanowires (ZnO NWs) were grown onto Indium Tin Oxide-coated glass substrates by a chemical bath deposition method. The growth of ZnO NWs carried onto unannealed and annealed Indium Tin Oxide-coated glass substrates. Substrates were
more » ... trates were annealed at 400 o C for 90 minutes at ambient using a horizontal furnace. This work also focused on the effect of annealing condition of ITO-coated glass substrate on nanowires morphology, crystal phase, optical band gap, and electrical properties. Substrate annealing was found to have a significant effect on the nanowires dimension. The nanowire's morphology was obtained by FESEM which the average diameter and length found on unannealed ITO-coated glass substrate were 674.18 ± 26.75 nm and 3.107 ± 0.446 μm. However, the nanowire's average diameter and length on annealed ITO-coated glass substrate were 393.50 ± 27.02 nm and 3.175 ± 0.321 μm. XRD analysis confirmed that ZnO nanowires on substrates with both conditions were able to promote the growth of crystal structure with crystal plane orientation of (101) and (100) belongs to hexagonal wurtzite structure. The near-band-edge (NBE) emission of ZnO nanowires obtained by using Photoluminescence which grown on unannealed and annealed ITO-coated glass substrates were observed at 380 nm (3.20 eV) and 384 nm (3.23 eV). FTIR analysis showed that ZnO absorption bands in the region between 450-500 cm -1 had arisen from interatomic vibrations due to the stretching of the Zn-O bond. The resistivity of ZnO nanowires obtained by using the four-point probe method on unannealed and annealed substrates was found to be 2.0675  10 -7 Ω cm and 2.0494  10 -7 Ω cm. Introduction Recently , industries have moved towards the use of nanostructured semiconductors to boost the efficiency of various devices, including optical sensors photonic research, flat panel displays, optical sensors, antireflection coatings, reflectors, interference filters, blue and green-emitting diodes (LED), and laser diodes [1-3]. One-dimensional nanostructures are useful materials for investigating the dependence of electrical and thermal transport or mechanical properties on dimensionality and size reduction [4]. They also play a significant role as interconnectors and functional units in the manufacture of electronic, optoelectronic, electrochemical, and electromechanical nano-devices [5]. Among the one-dimensional (1D) nanostructures, zinc oxide (ZnO) nanowire (NWs) is a promising nanomaterial for nanotechnology in today's research [6]. ZnO has wide bandgap (3.3 eV), large exciton binding energy (60 MeV) and high electron mobility (100-200 cm 2 V -1 s -1 ) [7] which makes it a suitable material for a wide range of devices, including piezoelectric transducers [8], Highlights  Zinc oxide nanowires (ZnO NWs) were grown onto Indium Tin Oxide-coated glass substrates by a chemical bath deposition method.  The growth of ZnO NWs carried onto unannealed and annealed Indium Tin Oxide-coated glass substrates.  Substrates were annealed at 400 o C for 90 minutes at ambient using a horizontal furnace.  Scanning electron microscopy measurement was carried out to evaluate the morphological properties of the grown ZnO NWs.  Results showed that the annealing process of the Indium Tin Oxide-coated glass substrates has a significant effect on the grown NRs dimensions.
doi:10.1016/j.rinp.2020.103185 fatcat:etpoegl2d5fzdd4ger5fqvifpa