Trapping-charging ability and electrical properties study of amorphous insulator by dielectric spectroscopy

Abstract

Usually, the trapping phenomenon in insulating materials is studied by injecting charges using a Scanning Electron Microscope. In this work, we use the dielectric spectroscopy technique for showing a correlation between the dielectric properties and the trapping-charging ability of insulating materials. The evolution of the complex permittivity (real and imaginary parts) as a function of frequency and temperature reveals different types of relaxation according to the trapping ability of the material. We found that the space charge relaxation at low frequencies affects the real part of the complex permittivity ε′ and the dissipation factor Tan(δ). We prove that the evolution of the imaginary part of the complex permittivity against temperature ε″=f(T) reflects the phenomenon of charge trapping and detrapping as well as trapped charge evolution Qp(T). We also use the electric modulus formalism to better identify the space charge relaxation. The investigation of trapping or conductive nature of insulating materials was mainly made by studying the activation energy and conductivity. The conduction and trapping parameters are determined using the Correlated Barrier Hopping (CBH) model in order to confirm the relation between electrical properties and charge trapping ability.

Temperature stable BaSrTiO3 thin films suitable for microwave applications

“…At low temperatures, a slight increase is visible for all frequencies which has already been reported in [6,9]. The increase at high temperatures, more visible for low frequencies, comes from the diffusion of charge carriers which increases when the temperature increases [26,27]. In the case of ferroelectrics, the low frequency diffusion is generaly attributed to an extrinsic contribution like electronic conduction or oxygen vacancy migration [16,27,28].…”