ZnO nanorod arrays have been synthesized on silicon wafers by chemical vapor deposition (CVD) technique with different temperature modes, without metal catalyst. With this method vertically aligned ZnO nanostructures were grown at the quite low temperatures. Modification of the method allowed to place silicon substrates in areas with different ratios of concentrations of the molecules in the vapor phase. Photoluminescence spectroscopy and electron microscopy studies have shown that morphologies and optical properties of nanorods depends on different ratios of concentrations of the molecules in the vapor phase.
Keywords: ZnO nanorods,chemical vapor deposition (CVD), photoluminescence
The arrays of ZnO nanorods were obtained on the sapphire substrates by means of pulsed laser deposition under the high pressure of argon. The conditions of synthesis were optimized, and their influence on the morphology of ZnO nanostructures were revealed. It is shown that the concentration of oxygen vacancies in ZnO nanorods can be changed by regulation of the synthesis temperature from 850 to 915 °. This process can be controlled by the ratio of intensities of the photoluminescence emission in the visible and ultraviolet regions. So, it allows to create nanostructures for UV photodetectors or chemosensors depending on the temperature choice.
Keywords: ZnO nanorods, laser deposition, PLD, photoluminescence
Structure of surface acoustic waves(SAW) of CO sensor was developed. SAW sensor include transceiving IDT and catoptric IDT, which is loaded on the impedance of ZnO nanorods. Peak of reflection SAW from IDT clearly observed as result Fourier transformation of time function of pulsed response. IDT loaded on resistance paralleled ZnO nanorods, which depends on the concentration of CO.
Keywords: ZnO nanorods, device on SAW, CO sensor
The sensor design on surface acoustic waves (SAW), representing the delay line with unidirectional inter-digital transducers (IDT) is considered. The factor of reflection of SAW from the unidirectional IDT loaded on impedance depending on value of resistance connected to it is investigated. On dependence of factor of reflection on size of resistance there is almost linear site at values of resistance more than 50 Ohm. The new design of the connected lattices of nanowire of zinc oxide, having the general resistance in a range of 50-250 Ohm which is connected to reflective IDT as loading is developed.
Keywords: passive sensors, ZnO nanowire, surface acoustic waves, interdigital transducer.