Electrical transport and resistance switching characteristics of BiFeO3/Nb:SrTiO3/GaAs heterostructure fabricated by pulsed laser deposition

Abstract

BiFeO 3 thin films were epitaxially grown on (001) GaAs substrate by pulsed laser deposition with Nb doped SrTiO 3 as a buffer layer. Piezoresponse force microscopy images exhibit effective ferroelectric switching of the heterostructure. The temperature-dependent current-voltage characteristics of the heterostructure reveal a resistance switching phenomenon and diode-like behavior with a rectifying ratio of 2 Â 10 2 at the applied voltage of 613.4 V. The electrical transport mechanism in the heterostructure has been illustrated by constructing the energy band structure. In addition, the resistance switching behavior in the heterostructure could be explained by the polarization modulation of the depletion region at the interface of the semiconductor and the ferroelectric layers.

Hysteretic Characteristics of Pulsed Laser Deposited 0.5Ba(Zr0.2Ti0.8)O3–0.5(Ba0.7Ca0.3)TiO3/ZnO Bilayers

“…In the case of our BCZT film, the current when the polarization points to the bottom electrode is always higher than when the polarization points to the top electrode. Although the present RS behavior is different from the one observed in ferroelectric diodes, where the RS behavior is dependent on the polarity of the readout electric field, similar polarization-dependent RS behavior has also been reported for other ferroelectric thin films and ferroelectric–semiconductor bilayers. ,, Moreover, in Figure S1 (see the Supporting Information) is shown an overlap of the P – E loops and the I – E . It is possible to observe that the coercive field and the switching field are similar.…”

“…The resistance of the ON state and OFF state was read out at 50 kV/cm and the RS ratio ( R OFF / R ON ) was found to be ≈66 and ≈3.3 × 10 4 for the BCZT thin films and the BCZT/ZnO bilayers, respectively. The observed RS ratio in the bilayers is superior to the one observed in other bilayers and in the epitaxial ferroelectric thin films. ,− …”

“…Although the present RS behavior is different from the one observed in ferroelectric diodes, where the RS behavior is dependent on the polarity of the readout electric field, similar polarization-dependent RS behavior has also been reported for other ferroelectric thin films and ferroelectric−semiconductor bilayers. 40,48,52 Moreover, in Figure S1 (see the Supporting Information) is shown an overlap of the P−E loops and the I− E. It is possible to observe that the coercive field and the switching field are similar. This confirms the coupling between the RS and the polarization flipping in both structures.…”

Ferroelectric Resistive Switching in High-Density Nanocapacitor Arrays Based on BiFeO3 Ultrathin Films and Ordered Pt Nanoelectrodes

“…For the ∼3 nm thick film, similar RS behavior with an ON/OFF ratio of 700 at 1 V was also observed (Figure S4b). It is noteworthy that such ON/OFF ratios are generally larger than those observed in ferroelectric thick films with a thickness above 100 nm, 9,10,24,25 and are also comparable with those observed in ultrathin films. 6,26−29 As further shown in Figure 5b, the ON/OFF current values, read at +2 V, only slightly deviate from device to device, indicating good reproducibility of the RS behavior in the Pt/BFO/SRO nanocapacitors.…”

Effect of Oxygen-deficiencies on Resistance Switching in Amorphous YFe0.5Cr0.5O3−d films

“…Furthermore, some studies demonstrate that the actual active switching region occurs in a nano-scale region between metal electrodes and RS layers, which suggests great potential applications for nonvolatile memory device 2 7 . Until now, a variety of materials had been investigated as RS layers in ReRAM devices, such as transition metal (TM) oxides 8 9 10 , ferroelectric films 11 12 13 , and perovskite oxides 14 15 16 . Many models have been proposed to explain the RS behaviors, such as conductive filament (CF) model 17 18 19 , Schottky barrier model 20 , and space-charge limited current model 21 .…”