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With the increasing wide application of organic or polymer substrates, amorphous transparent conducting oxides (a-TCOs) had been widely applied to thin-film transistors, polymer/organic solar cells, electrochromic devices, electromagnetic shielding and other areas due to the combined transparency and conductivity as well as stable properties, processing compatibilities with current technologies and free of post-annealing. A-TCOs films were not the amorphous counterpart of crystalline TCOs but prepared with special elements under certain conditions. After the brief introduction to the working principle of TCO, the even general amorphous transparent semiconducting oxide was addressed intensively. It was worth to note that compared with c-TCOs and classic silicon, the features of electronic structure of a-TCOs were the cations with special configuration (n-1)d10ns0. The stable amorphous structure and excellent properties can be conserved due to larger overlap integral between the adjacent atoms, high mobility and robustness. Particularly, the near range structure characterization such as the medium range order, band structure described by density of states and the metastability of amorphous structure and the related properties were introduced as well. Afterwards, the properties and features of N-type and P-type a-TCOs were exampled in details, especially the indium-based systems, such as excellent a-In-Zn-O films. Less example of P-type a-TCOs were shown as no general principle had been formed for that. Finally, many state-of-art applications including thin-film transistor are introduced. Based upon the current status and emerging trend, three potential research perspective directions of a-TCO have been delivered:(1) to further investigate non-indium based a-TCO; (2) to develop on the P-type TCO with novel principle and material systems; (3) to enable the alternative application that occupied by conventional silicon previously.

Oxide-metal-oxide (OMO) multilayer film has attracted increasing interest due to its high performance, including the high optical transparency and low electric resistivity, and has been considered a promising substitute for the conventional indium tin oxide (ITO) film. In this work, we studied the role of growth parameters for the performance of sputtered ITO/Ag/ITO multilayer film. ITO/Ag/ITO film with superior properties of transmittance of 89.1% and sheet resistance of 8 Ω/□ was prepared. The effects of deviation of film thickness on the optical and properties were investigated systematically. Ultrathin ITO1−x film with thickness of less than 5 nm covers the active Ag surface to avoid Ag oxidation effectively, resulting in both high transmittance and conductivity. The X-ray photoelectron spectroscopy depth profile analysis indicates the role of ultrathin ITO1−x film on Ag surface oxidation. This work provides a guideline to fabricate high-quality OMO-based films and devices. [ABSTRACT FROM AUTHOR]

In this paper, the defects of Al doped ZnO films generated by magnetron sputtering in the deposition processes are comprehensively investigated. It is found that oxygen ion bombardment deteriorates the crystallinity and generates oxygen related defects, such as oxygen interstitials (O i ), chemisorbed oxygen at the grain boundaries (O GB ), and oxygen vacancies (V O ). O i and O GB decrease the carrier concentration and mobility of the pristine films remarkably, but they can be removed by hydrogen annealing. However, the grain boundary scattering originated from poor crystallinity cannot be reduced by the annealing below 450 °C. Moreover, the in-situ temperature-dependent resistivity measurement under hydrogen atmosphere suggests that hydrogen atoms are incorporated into the ZnO: Al films and interact with V O . We propose that there are two energetically favorable states for the incorporated hydrogen. The defect configurations of (H 2 ) i and H O + H i are assigned to the high resistivity state (HRS) and low resistivity state (LRS) respectively and the switching between these two states is activated by V O and mediated by a metastable state (H 2 ) * O . The transformation between these two resistivity states leads to a hysteresis loop during the heating and cooling process. [ABSTRACT FROM AUTHOR]