Modeling of hysteretic Schottky diode-like conduction in Pt/BiFeO3/SrRuO3 switches

Abstract

The hysteresis current-voltage (I-V) loops in Pt/BiFeO3/SrRuO3 structures are simulated using a Schottky diode-like conduction model with sigmoidally varying parameters, including series resistance correction and barrier lowering. The evolution of the system is represented by a vector in a 3D parameter space describing a closed trajectory with stationary states. It is shown that the hysteretic behavior is not only the result of a Schottky barrier height (SBH) variation arising from the BiFeO3 polarization reversal but also a consequence of the potential drop distribution across the device. The SBH modulation is found to be remarkably lower (<0.07 eV) than previously reported (>0.5 eV). It is also shown that the p-type semiconducting nature of BiFeO3 can explain the large ideality factors (>6) required to simulate the I-V curves as well as the highly asymmetric set and reset voltages (4.7 V and −1.9 V) exhibited by our devices.

Toward Intrinsic Ferroelectric Switching in Multiferroic BiFeO3

“…The observed current (I obs ), the displacement current (I disp ¼ I FE þ I LD þ I NLD ), and the (leakage) current (I L ) arising from Schottky barriers [20][21][22][23][24]28,29] at the metal and ferroelectric interfaces and resistive leakage in the ferroelectric [ Fig. 1(b)] are given by:…”

“…By subtracting the nonswitching transient from the switching transient, we determine the contribution to measured current arising from switching of the ferroelectric polarization alone [7,[16][17][18]. Any contribution to currents arising from leakage, interfacial Schottky barriers and nonlinear dielectric effects (present in all ferroelectric capacitors [20][21][22][23][24]) is subtracted out when we analyze the difference between the switching and nonswitching current transients.…”

Modeling of the conduction characteristics of voltage-driven bipolar RRAMs including turning point effects

“…This symmetry condition can be modified according to the particular features exhibited by each device [9]. Importantly, notice that (4) always yields a zero-crossing curve (I(V=0)=0) regardless of its parameter values.…”

The effects of grain size on electrical properties and domain structure of BiFeO3 thin films by sol–gel method

“…Charged domain walls show metallic behavior and are correlated with the polarity of the majority carriers [53]. Thus, the majority carriers including positively charged hole or V ÁÁ O assemble on ''tail to tail'' domain wall in p-type BiFeO 3 system [54,55] and result in the increase of leakage current of BFO thin films with ''tail to tail'' domain walls. As mentioned above, there are ''tail to tail'' domain walls in the BFO thin films with small grain size (G a = 87 nm), which lead to its higher leakage current density.…”