Abstract
Controlling properties of one-dimensional (1D) semiconducting nanostructures is essential for the advancement of electronic devices. In this work, we present a low-temperature hydrothermal growth process enabling density control of aligned high aspect ratio ZnO nanowires (NWs) on seedless Au surface. A two order of magnitude change in ZnO NW density is demonstrated via careful control of the ammonium hydroxide concentration (NH4OH) in the solution. Based on the experimental observations, we further, hypothesized the growth mechanism leading to the density controlled growth of ZnO NWs. Moreover, the effect of NH4OH on the electrical properties of ZnO NWs, such as doping and field-effect mobility, is thoroughly investigated by fabricating single nanowire field-effect transistors. The electrical study shows the increase of free charge density while decrease of mobility in ZnO NWs with the increase of NH4OH concentration in the growth solution. These findings show that NH4OH can be used for simultaneous tuning of the NW density and electrical properties of the ZnO NWs grown by hydrothermal approach. The present work will guide the engineers and researchers to produce low-temperature density controlled aligned 1D ZnO NWs over wide range of substrates, including plastics, with tunable electrical properties.
Highlights
Controlling properties of one-dimensional (1D) semiconducting nanostructures is essential for the advancement of electronic devices
The growth mechanism leading to the large NW density variations with varying NH4OH concentrations is discussed
We found that the concentration of ammonium hydroxide plays a crucial role in controlling the NW area density
Summary
Controlling properties of one-dimensional (1D) semiconducting nanostructures is essential for the advancement of electronic devices. Employing high resolution e-beam lithography, Consonni et al.[25] reported position, vertical alignment, dimensions, and polarity controlled growth of ZnO NWs over large surface areas Adoption of these approaches are restricted due to many limitations such as: (i) use of expensive and complicated equipment added to cost and complexity of the final device, (ii) incompatibility with flexible substrates, and (iii) unscalability at industrial level. Seedless density controlled growth of ZnO NWs, on Au surface, has been proposed eliminating the use of any lithography technique[27] Such a growth approach has shown distinctive advantages, including: (i) low growth temperature enabling direct integration of NWs for the fabrication of functional devices onto organic substrates, (ii) tight control over size, orientation, and density of produced NW, and (iii) cost-effective. The detailed statistical data of mobility and free charge density for ZnO NWs, grown with different NH4OH concentrations, will be presented
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
