Interface state density and dielectric properties of Au/n-GaP Schottky diode

Abstract

The temperature and frequency dependent capacitance and conductance measurements of Au/n-GaP Schottky diode were carried out in the 200–400 K and 1 kHz–1 MHz range, under different bias voltages. The obtained interface state density (Nss) and the carrier life time (τ) were evaluated from the measured data. The values of Nss and τ depend strongly on the applied voltage and temperature. The effect of the interface states of the device under different conditions was also analyzed. The series resistance (Rs) of the device was evaluated under different frequencies and temperature conditions using Nicollian and Goetzberger method. The dielectric parameters like dielectric constant (ε′), dielectric loss (ε″), loss tangent (tan δ), and ac electric conductivity (σac) were analyzed under complex permittivity (ε*) formalism. The variations of ε′ and ε″ with frequency and temperature are attributed to the interfacial polarization and the temperature induced restructuring and reordering of interface state density. The activation energy of the interface states shows three different linear regions corresponding to activation energy values of 0.013, 0.034, and 0.061 eV.