Influence of Ag Doping on the Microstructural, Optical, and Electrical Properties of ZrSiN Coatings Deposited through Pulsed-DC Reactive Magnetron Sputtering

Abstract

The functional properties of the transition-metal nitride coatings can be modified by adding noble metals such as silver. The incorporation of these elements has been demonstrated to be a good strategy for improving the electrical, optical, and mechanical responses of transition-metal nitride coatings. In this investigation, we report the production of Ag-ZrSiN coatings with varying silver atomic contents, deposited using pulsed-DC reactive magnetron sputtering. The effect of the incorporation of silver on the microstructure, the morphology, and the optical and electrical properties was investigated. The results revealed a nanocomposite structure of Ag-ZrSiN with nc-Ag/nc-ZrN embedded in an amorphous SiNx phase. The electrical resistivity decreased upon the incorporation of Ag from 77.99 Ω·cm to 0.71 Ω·cm for 0.0 and 12.0 at.% of Ag, respectively. A similar decreasing trend was observed in the transmittance spectra of the coatings as the silver content increased. For the Ag-ZrSiN coating, the transmittance values decreased within the wavelength range of 2500–630 nm and then remained constant down to 300 nm, at about 13.7%. Upon further increase of the silver concentration up to 12 at.%, the transmittance values continued to decrease between 2500 and 630 nm, reaching approximately zero at 630 nm, indicating that the coating becomes opaque within that spectral range.

Optimizing Sputter Deposition Conditions of Silver Thin Films Used in Low-Emissivity Coatings in an In-Line Deposition System

“…This type of coating typically consists of thin layers of transparent oxides or nitrides, combined with thin layers of a noble metal, such as gold, silver, or copper [4][5][6]. Silver is the most commonly used noble metal, due to its more suitable optical properties [7,8], which allow the coatings to remain transparent in the visible range, while achieving a high infrared reflectance. The transparent thin layers are essential for adjusting the optical properties (often acting as an anti-reflective effect, to maximize visible transmission), but they also serve other functions, such as acting as a seed layer to improve silver deposition and enhance adhesion, or protecting the silver layer from exposure to the atmosphere [9][10][11][12][13].…”