Transparent conductors as solar energy materials: A panoramic review

A review of the sputtered film stress literature shows that the intrinsic stress can be tensile or compressive depending on the energetics of the deposition process. Modeling studies of film growth and extensive experimental evidence show a direct link between the energetics of the deposition process and film microstructure, which in turn determines the nature and magnitude of the stress. The fundamental quantities are the particle flux and energy striking the condensing film, which are a function of many process parameters such as pressure (discharge voltage), target/sputtering gas mass ratio, cathode shape, bias voltage, and substrate orientation. Tensile stress is generally observed in zone 1-type, porous films and is explained in terms of the grain boundary relaxation model, whereas compressive stress, observed in zone T-type, dense films, is interpreted in terms of the atomic peening mechanism. Modeling of the atomic peening mechanism and experimental data indicate that the normalized moment...

Intrinsic stress in sputter-deposited thin films

Perspectives on oblique angle deposition of thin films: From fundamentals to devices

ZnO thin films produced by magnetron sputtering

The article reports on flexible hard nanocomposite coatings prepared by magnetron sputtering. It is shown that the flexible hard nanocomposite coatings (i) represent a new class of coatings which are simultaneously hard, tough and resistant to cracking, (ii) exhibit high values of the hardness H and effective Young's modulus E* ratio H/E* ≥ 0.1, elastic recovery We ≥ 60%, compressive macrostress σ < 0 and dense, void-free microstructures, and (iii) are formed in the zone T of the Thornton's Structural Zone Model (SZM); here E* = E/(1 − ν2), E is the Young's modulus and ν is the Poisson's ratio. The magnetron sputtering, which is a very powerful process used in the preparation of nanocomposite coatings, is described in detail. The basic principles of the formation of the flexible hard coatings are also described in detail. It is shown that the key parameters which determine the formation of these coatings are (1) the energy Ep = Eca + Ebi delivered to the growing coating by condensing atoms (Eca) and bombarding ions (Ebi) (the non-equilibrium heating), (2) the substrate heating controlled by the substrate temperature Ts (the equilibrium heating) and (3) the melting temperature Tm of the coating material. The flexible hard coatings have a huge application potential. Four examples of flexible coatings are given: (1) flexible protective coatings, (2) flexible functional coatings, (3) flexible over-layer preventing cracking of brittle coating and (4) flexible multilayer coating. Also, the principle of low-temperature sputtering of flexible nanocomposite coatings is described in detail. Finally, trends for future development of these nanocomposite coatings with unique properties are given.

A. V. Demchishin

Papers

Structure and properties of thick condensates of nickel, titanium, tungsten, aluminum oxides, and zirconium dioxide in vacuum.