Piezoresistive properties of amorphous carbon based nanocomposite thin films deposited by plasma assisted methods

The survey of recently completed research concerning relation between the used technology of deposition (plasma enhanced chemical vapor deposition, magnetron sputtering), reagents, structure and piezoresistive properties of diamond like carbon (DLC) films containing different nanoparticles is presented. The effects of systematically varied deposition conditions during plasma assisted methods, such as bias voltage, gas flow ratio on chemical composition, structure and properties of diamond like carbon nanocomposites are discussed, and attention is paid to the origin of piezoresistive effect and role of matrix on the main parameters, such as gauge factor and temperature coefficient of resistance. The role of the carbon matrix and the size of silver nanoparticles in the DC magnetron deposited diamond like carbon films are analyzed. It is shown that according to the Raman scattering the sp3/sp2 ratio in the silver containing diamond like carbon (DLC:Ag) films increases with the acetylene/argon flux ratio. The surface plasmon resonance related peak was observed in the optical absorbance spectra of DLC:Ag films when silver atomic concentration in films reached 3.7%. It was revealed that the gauge factor of silver containing DLC films is dependent on both structure of the diamond like carbon matrix and on size of the silver clusters.

► Silver containing diamond like carbon films (DLC:Ag) were investigated. ► DLC:Ag films deposited by unbalanced direct current reactive magnetron sputtering. ► Gauge factor (GF) of the DLC:Ag films depends on structure of the DLC matrix. ► GF of the films depends on Ag atomic concentration and size of the Ag nanoclusters. ► Temperature coefficient of resistance of DLC:Ag films depends on Ag clustering.