Electrodeposition Of The Micro/Nano Structures Of SnO2

The science in nano-materials is to study the characteristics of the materials, and to manufacture products with specific features, to achieve a leap in production of a subject, constitute the foundation for a new era of 21st century science and technology. As the sensitive nature of nano-materials depends on its micro- structure, design and preparation of nano-materials and nano-structure has become the important way to discovery the new effects and to explore the development of new materials and micro nano-devices. How to assemble the units for the one-dimensional nanostructures with nano-scale in radial and long length in axial has always been the goal of condensed matter physicists, materials scientists, chemists.There are many methods to preparing the micro/nano structures, many are mixed together and difficult to achieve separation of the structure. In this paper, freezing method was used to construct a quasi-two-dimensional ultra-thin liquid layer which limits the growth of the materials. The SnO2 micro-nanowire parallel arrays was growing on the plane silicon substrates firstly, which narrows the scope of utilization space, and thus more conducive to the current development trend of micro-devices.As a N-type semiconductor material with broadband gap, the band gap width reaches to 3.6eV, with the high reflectivity in infrared range, high transparency in the visible spectrum region, significant gas properties, low resistivity and many unique optical properties, SnO2 has become an important part of the third generation semiconductor materials. It was widely used in gas and humidity sensor, battery anode material, thin film resistors, SIS structure heterojunction, the glass surface protection layer, and won the great concern of researchers.Our research has focused on the preparation of SnO2 micro nanowires, characterization and preliminary of growth mechanism. By varying the experimental conditions, such as the electrolyte concentration, PH value, the applied DC voltage and square wave pulse voltage and copper electrode to induce the different morphologies of micro/nano structures. The different morphologies of SnO2 micro/nano structures were characterized by scanning electron microscope (SEM). A variety of novel morphologies, such as vertical branching,parallel array,periodicity,gridding,bamboo,net were observed.A X-ray diffractometer and a transmission electron microscopy (TEM) were employed to study structure and chemical composition of deposits. Including EDS,XRD,TEM,HRTEM pictures. The analysis showed that the samples were tetragonal structure SnO2 with the high orientation.The growth mechanism of SnO2 one-dimensional nano-materials in two-dimensional electrodeposition layer has been explained and the analysis mainly on the branching of micro-nanowires and the phenomenon of periodic growth induced by pulse voltage. It pointed that the phenomenon of branching is closely related to the electronic distribution on the growing front, whereas the periodic growth phenomena is closely related to the relative concentration between the electron and tin cation on the growing front. This relative concentration depends on the level of voltage pulse transition, the concentration of electron on the changes rapidly, while the change of tin cation concentration near the growing front exists hysteresis effect.