Introduction
Zinc oxide (ZnO) is at the forefront of semiconductor compounds II-VI with
potential applications due to the high optical transmittance in the visible region due
to its large band gap and electrical conductivity at room temperature; these
characteristics make it an ideal candidate for applications such as transparent
conductive electrode, window layers in the solar cell applications and gas
sensors[1]. The nanoscale structure of zinc oxides plays an important role in the
devices performance, as an example in gas sensor devices because the large area
will enhance the properties of gas sensors and, moreover, have safe biological
properties (as a non-toxic substance) which makes ZnO very attractive for vital
applications. The simple preparation methods of producing ZnO thin films give
them the potential to be studied. ZnO can be applied as thin layersin transistor
applications[2], and is considered a rotational electronic material[7]. Zinc oxide
films can be prepared using various techniques, including lamination, chemical
vapor, sol-gel and pyrolysis spray. Recently, due to its excellent physical properties
and potential technological applications, ZnO has attracted considerable attention.
ZnO is an n-type semiconductor with wurtzite structure of hexagonalcrystals.as
shown in Fig.1(A).