Approaches to rid cathodic arc plasmas of macro- and nanoparticles: a review

Mendelsberg

Applied Surface Science

et al. 2013

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Title AbstractIndium doped cadmium oxide (CdO:In) films with different In concentrations were prepared on low-cost glass substrates by pulsed filtered cathodic arc deposition (PFCAD). It is shown that polycrystalline CdO:In films with smooth surface and dense structure are obtained. In-doping introduces extra electrons leading to remarkable improvements of electron mobility and conductivity, as well as improvement in the optical transmittance due to the Burstein-Moss effect. CdO:In films on glass substrates with thickness near 230 nm show low resistivity of 7.23×10 -5 Ωcm, high electron mobility of 142 cm 2 /Vs, and mean transmittance over 80% from 500-1250 nm (including the glass substrate). These high quality pulsed arc-grown CdO:In films are potentially suitable for high efficiency multi-junction solar cells that harvest a broad range of the solar spectrum. Keywords:In doped cadmium oxide; pulsed filtered cathodic arc deposition; transparent conductors IntroductionTransparent conducting oxides (TCOs) have attracted much attention due to their tremendous importance in optical and electrical applications such as displays, touch-screens, thin film solar cell technology and for transparent conducting electrodes in general [1,2]. For solar cell applications, high mobility TCO contacts with a sheet resistance of <10 Ω/□ and an optical transmission >80% over the visible to near infrared wavelengths (bandgap >3 eV) can enhance the efficiency [3]. This is particularly effective for multi-junction solar cells which consist of different semiconductor stacks with appropriately matched bandgaps that are tuned to increase the spectral response over the entire solar spectrum [4]. Therefore, in addition to maintaining high conductivity, improving the visible to near infrared transparency of TCO films is of great importance for applications in high performance multi-junction solar cells.

Section: Methodsmentioning

confidence: 99%

Transparent and conductive indium doped cadmium oxide thin films prepared by pulsed filtered cathodic arc deposition

Mendelsberg

Applied Surface Science

et al. 2013

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Solid State Communications

“…The sources (one for Ag, the other for the transition metal) operated in repetitively pulsed mode with arc pulses of 1.2 kA amplitude, 600 µs duration, and a repetition rate of 1.6 p.p.s. Each source had a 90° magnetic filter (a curved, open solenoid) to remove unwanted metal debris ("macroparticles") from the plasma [8]. The chamber was cryogenically pumped to a base pressure of about 10 -4 Pa; no process gas was needed or used.…”

Section: Methodsmentioning

confidence: 99%

Smoothing of ultrathin silver films by transition metal seeding

Anders

Byon

Kim

et al. 2006

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Abstract.The nucleation and coalescence of silver islands on coated glass was investigated by insitu measurements of the sheet resistance. Sub-monolayer amounts of niobium and other transition metals were deposited prior to the deposition of silver. It was found that in some cases, the transition metals lead to coalescence of silver at nominally thinner films with smoother topology. The smoothing or roughening effects by the presence of the transition metal can be explained by kinetically limited transition metal islands growth and oxidation, followed by defect-dominated nucleation of silver.LBNL-59621 revised Accepted

Surface and Coatings Technology

“…The high surface roughness determined in the coated conditions is assumed to result from the presence of protruding coating surface asperities (macroparticles) in the TiNcoatings. These micrometer-sized heterogeneities are typical for coatings grown by cathodic arc evaporation and they may negatively impact coating quality and surface finish [48][49][50][51]. Finally, grinding effects at the surface level are evidenced in terms of not only roughness but also texture.…”

Section: Surface Integrity Characterization: Roughness Subsurface Damentioning

confidence: 99%

Contact damage resistance of TiN-coated hardmetals: Beneficial effects associated with substrate grinding

Yang

Marro

Trifonov

et al. 2015

Contact loading is a common service condition for coated hardmetal tools and components. Substrate grinding represents a key step within the manufacturing chain of these coated systems. Within this context, the influence of surface integrity changes caused by abrasive grinding of the hardmetal substrate, prior to coating, is evaluated with respect to contact damage resistance. Three different substrate surface finish conditions are studied: ground (G), mirror-like polished (P) and ground plus heat-treated (GTT). Tests are conducted by means of spherical indentation under increasing monotonic load and the contact damage resistance is assessed. Substrate grinding enhances resistance against both crack nucleation at the coating surface and subsequent propagation into the hardmetal substrate. Hence, crack emergence and damage evolution is effectively delayed for the coated G condition, as compared to the reference P one. The observed system response is discussed on the basis of the beneficial effects associated with compressive residual stresses remnant at the subsurface level after grinding, ion-etching, and coating. The influence of the stress state is further corroborated by a lower resistance against damage for the coated GTT specimens. Finally, it is proposed and preliminary validated that substrate grinding also enhances damage tolerance of the coated system when exposed to contact loads. M.P. Johansson-Jõesaar and L. LlanesDear Professor Matthews, Please find attached electronic files corresponding to our contribution on contact damage resistance of TiN-coated hardmetals: beneficial effects associated with substrate grinding, which we (all authors do agree to the submission of the manuscript) offer for publication in Surface and Coatings Technology.I hope it is found satisfactory. (Procedia CIRP, Volume 13, 2014, Pages 257-263).(Authors) R1 is right about connection between results published in our contribution to the 2nd CIRP Conference on Surface Integrity (reference [27] in the submitted manuscript) and those presented in this paper. However, the two papers are distinctly different and cover completely different research topics and contain different data. The former focuses on "ground hardmetals" and "flexural strength/fractography", whereas the current one deals with "coated hardmetals" and "contact damage". Hence, we find R1's comment regarding "similar results" inappropriate. (Authors) Co binder effects on residual stresses are not neglected, and our writing may be blamed for such misunderstanding. Residual stresses induced by grinding are "macrostresses" evaluated in the WC phase and assumed to be representative of the whole WC-Co composite. They are different from the "microstresses" (different for each individual phase) that arise due to the difference in thermal expansion between the binder and the carbide as the material cools from liquid-or solid-phase sintering. In cemented carbides with WC as the carbide, the WC is taken as a reliable reference phase because it remains stoichiometric...