ZnO nanowire arrays – Pattern generation, growth and applications

Abstract

761 203 7422, Web: http://www.imtek.de/ nano/ ZnO nanowires and related materials are in the focus of attention for electronic, optical or sensor applications. However, size, position and arrangement control are essential conditions for the development of future nanowire based devices. Various kinds of template methods including nanosphere lithography and UV laser interference lithography are powerful tools for the preparation of the starting metal catalyst arrays and will be demonstrated and discussed. However, only if the growth mechanism and its guiding parameters are understood in detail, the template will force a pattern arranged growth of nanowires. The paper gives an overview of the various kinds of growth modes for vertical arranged nanowires. Specific experimental conditions establishing the VS or the VLS growth are discussed. In addition, insight is given why the patterning is not all the time conserved and how to overcome these obstacles. In the second part different kinds of applications are summarized. Electronic properties are discussed based on metal-semiconductor-metal devices. The influence of a core-shell nanowire structure on the optical properties is demonstrated. In addition, a simple approach for ZnO nanowire based gas sensors is discussed and shown. As a last example, the transfer of Al 2 O 3 coated nanowires into spinel tubes is reported.

Tipping solutions: emerging 3D nano-fabrication/ -imaging technologies

“…This reduces the number of processing steps required to make a device and enables fast prototyping. Despite its inherent 3D fabrication capability, FEBID has been mostly used to make planar structures, such as formation of electrical contacts [67][68][69] or repair of photolithography masks [70]. This restriction arose mostly due to the complexity of the deposition process as it involves many parameters.…”

ZnO nanowire photodetectors based on Schottky contact with surface passivation

“…Semiconductor nanowires (NWs) have been studied intensively as potential active materials in optoelectronics and electronics because of their beneficial characteristics in structure, function, and fabrication [1][2][3][4][5][6]. Among these NWs, ZnO is an important wide-gap semiconductor with a band gap of 3.3 eV, which demonstrates strong absorption in ultraviolet (UV) light, thereby leading to evident electronic transitions from valence band to conduction band.…”

Luminescence and energy transfer processes in ensembles and single Mn or Tb doped ZnS nanowires

“…Bottom-up growth methods have attracted, therefore, a great deal of research interest in the past decade. [1][2][3][4] The selfassembled approach leads not only to materials of high quality and purity but also of rather low cost in comparison to standard top-down methods. Particularly, semiconductor nanowires emerged in the recent years 5,6 as promising building blocks for nanoscale optoelectronic devices.…”