ABSTRACT
Various techniques, such as electron beam evaporation, ion beam assisted deposition, and ion implantation are used for growth of the ITO thin films. However, the vacuum processes have disadvantages of inefficiency and source wasting because ITO particles are exhausted onto inner wall of the vacuum chamber as well as coated onto substrate. As we know, fabricating the Transparent Conduction Oxides (TCOs) thin films in a non-vacuum process is an important issue for
1 INTRODUCTION
Transparent Conducting Oxide (TCO) thin films, such as zinc oxide, tin oxide, indium tin oxide, cadmium oxide, and cadmium tin oxide, are used for a wide range of important applications, such as transparent electrodes in LCDs, organic light emitting diodes, solar cells, and plasma display panels. TCO thin films can also be used as transparent heat reflecting windows as well as surface heaters for cameras, lenses, mirrors, car windows, gas sensors, and ohmic contacts for surface-emitting diodes (Tuna et al. 2010). In view of their practical importance, many basic researches and developments have been carried out on the electrical and optical properties of indium oxide based ceramics. In particular, considerable attention has been devoted to the study of indium tin oxide (or called as tin doped indium oxide, abbreviated as ITO) thin films with the intention of their utilization in technology (Tahar et al. 1998). After being developed, ITO-based materials become one of the
lowering down the fabrication price and decreasing the source wasting (Toki et al. 1997). However, only few efforts have been made to systematically investigate the TCOs by a SPM method (Wu et al. 2013, Wu et al. 2013). Thus, price of In increases in proportional to the market growth, and the reduction of In consumption is extensively required. In order to reduce In consumption effectively, the concentration of In should be reduced. In this study, the first important issue is that Al2O3 is used to substitute In2O3 for the decrease in price of In2O3-based TCO thin films. Therefore, the In2O3, Al2O3, SnO2 (In:Al:Sn = 68.8: 11.8:8.4, IATO) was used as the main composition. The second issue of this study is that the IATO is ground into nano-scale powers, and SPM method is used to develop the IATO TCO thin films. The effects of the different annealing temperature on the physical and electrical properties of the IATO thin films, including the surface morphology, cross-section observation, crystallinity, carrier mobility, carrier concentration, and resistivity, were well investigated.
