Temperature dependency of impedance, dielectric, and conductivity properties for Si-p/beta-FeSi2-n heterostructures created through facing target sputtering

Abstract

To connect thermal dependency with Si-p/beta-FeSi2-n heterostructure efficiency, this work explored the impedance characteristics accompanied by dielectric and conductivity properties under different temperatures of 160–400 K. The Nyquist impedance plots for the heterostructures showed a semicircular arc that shrank as the temperature increased. These can be equivalently interpreted as a loop of single resistance paralleled to single constant phase element representing the heterostucture which also paralleled to inductive elements representing the inductive effect, serially connected to electrode resistance. The dielectric properties implied a shift in behavior for the relaxation process since donor-acceptor deionization occurred when the temperatures reached 320 K or higher due to shorter relaxation time and higher thermal dissipation. The conductivity properties indicate that the transport mechanism at 180 K or lower involves a prolonged transitional movement before transitioning into localized hopping at higher temperatures, corresponding to faster carrier movement. The relaxation and activation energy of the heterostructure reveal drastic transition of the energy from a low temperature of 160–240 K to a higher temperature of 320–400 K, where the electrical mechanism of the heterostructures become highly dependent on the temperature likely due to the high carrier density based on unevenly high activation energy.