Abstract
The dielectric properties of Al/Dy2O3/porous Si heterostructure were investigated in the temperature range 270–420 K by capacitance and conductance-frequency measurements. The G (f) characteristics were well described by the modified law GAC = A1fS1 + A2fS2, and the results showed frequency dependent and evidence of two different behaviors in ac conductance. It was found that the Dy2O3 film exhibited a thermally activated conductance, i.e., G (T) = G0 exp (Ea/kBT), over a considerable temperature range. Activation energy is deduced from the variation of conductance with temperature using the Arrhenius relationship. The Arrhenius plot shows two activation energies revealing the presence of two distinct trap states in the chosen temperature range. The effect of temperature on series resistance (Rs) and interface state density (Nss) were investigated. Further, in order to gain an insight into the electric nature of the elaborated structure, the Cole-Cole diagrams are also investigated at different temperatures. Impedance analysis on the structure help to understand the contributions of electrical conductivity and interfacial polarization so, the Al/Dy2O3/porous Si heterostructure is accurately modeled as a two parallel elements (RC) network placed in series.
•The dielectric properties of Al/Dy2O3/porous Si heterostructure were investigated at different temperatures for the first time.•The G (f) characteristics described by the modified law.•Two activation energies revealing the presence of two distinct trap states.