Fabrication and Characterization of ZnO Nanorods on Multiple Substrates

Abstract

In this study, we present the fabrication and characterization of ZnO nanorods (NRs) grown on p-Si, gold (Au) and nickel (Ni) coated on Si wafer, indium tin oxide (ITO), and quartz substrates. The aqueous chemical growth method is used for the vertical growth of ZnO NRs on multiple substrates. The samples are characterized with scanning electron microscope and energy dispersive X-ray spectroscopy to probe into the growth, alignment, density, diameter, and length of ZnO NRs on multiple substrates. It is found that under same conditions, like growth temperature, growth time, and solution concentration, ZnO NRs on ITO and quartz have same length but comparatively larger diameter than on other samples. The effects of growth time on the diameter and length of ZnO NRs are also explored. All the samples are characterized with probe station to look at the current-voltage (I-V) behavior of ZnO NRs on multiple substrates. It is found that ZnO NRs on p-Si show a simple p-n heterojunction diode like behavior. ZnO NRs grown on Au- and Ni-coated Si wafers show Schottky I-V characteristic behaviors while ZnO NRs on ITO show a simple ohmic I-V response with comparatively higher level of current. Finally, the I-V response of ZnO NRs on p-Si is also studied under ultraviolet illumination. Because of the photo-generated carriers in ZnO, the sample shows higher level of current upon illumination.

Microwave-assisted Facile and Ultrafast Growth of ZnO Nanostructures and Proposition of Alternative Microwave-assisted Methods to Address Growth Stoppage

“…The seeds were dropped and spin coated at 3000 rpm on the substrate for 30 seconds, and the process was repeated for a number of times that depended on the thickness of the required thin film. For the first four coatings, the sample was annealed at 110 °C, and for the last coating, it was annealed at 310 °C for 30 mins so that the adhesive and sticky nucleation layer of the seeds was formed on the surface of the substrate 40 .…”

Growth Method-Dependent and Defect Density-Oriented Structural, Optical, Conductive, and Physical Properties of Solution-Grown ZnO Nanostructures

“…ZNS growth depends upon growth temperature to facilitate the chemical reactions, and where the reaction rates depend strongly on the heat transfer method [ 18 , 19 ].…”

“…The most eminent methods for ZNS synthesis are gas phase reaction, liquid phase deposition, metal organic chemical vapor deposition (MOCVD), vapor liquid solid, thermal evaporation, pulsed laser deposition, molecular beam epitaxy (MBE), thermal evaporation, and aqueous chemical growth (ACG) [ 13 , 14 , 15 , 16 , 17 ]. ACG, also called the hydrothermal method, is one of the most effective methods for ZNS growth due to simple setup, low cost, and green chemistry aspects [ 18 ]. However, the dilemma envisaged with the process are long heating times and temperature gradients in the solution autoclave, which can affect the structural and crystalline properties of ZNSs.…”

Intrinsic Control in Defects Density for Improved ZnO Nanorod-Based UV Sensor Performance

“…The next step was the vertical ZNR fabrication. S1 and S2 were fabricated using a convective hydrothermal method while S3 was fabricated by the irradiative MAG method [9,15,16]. Three different solutions were prepared for S1, S2, and S3 during this process.…”

“…The topic is so pervasive that it leads the researchers to intensively probe into the defect density-oriented changes in optoelectronic characteristics of ZnO [10]. ZnO has been fabricated using multiple methods, such as pulse laser deposition, vapor-liquid-solid, metal organic chemical vapor deposition, molecular beam epitaxy, hydrothermal aqueous chemical growth, and microwave-assisted growth (MAG) methods [11][12][13][14][15][16]. ZnO defect density directly depends on the growth method.…”