Bipolar resistive switching behavior of bilayer β-Ga2O3/WO3 thin film memristor device

This article investigates the bipolar resistive switching behavior of bilayer Au/β-Ga2O3/WO3 thin film (TF)/Ag heterostructure memristor device deposited using an electron beam evaporation technique. The purity of the deposited sample was confirmed by the XRD and FESEM with EDS characterizations. The root mean square roughness(RRMS) of single layer WO3 TF and heterolayer of Ga2O3/WO3 TF were obtained from the AFM analysis as 4.56 nm and 2.20 nm, respectively. The presence of more oxygen vacancies in WO3 sample was also confirmed by the XPS analysis. The optical measurement of the sample also revealed a bandgap of ∼ 4.35 eV for β-Ga2O3 TF and ∼ 3.66 eV for WO3 TF. Moreover, the bilayer Au/β-Ga2O3/WO3 TF/Ag heterostructure memristor device demonstrated bipolar resistive switching behavior with a good resistance ratio of ∼ 182, an endurance of 300 cycles, and a data retention of 103 s at room temperature. The device also yielded a low SET power of 1.17 mW (at 1.74 mA, +0.67 V) and a low RESET power of 2.50 mW (at 7.16 mA, – 0.35 V). The logarithmic current-voltage (I-V) relationship revealed that the switching behavior of the memristor device is mainly dominated by Ohmic conduction in LRS as well as Child’s square law, TCLC and Ohmic conductions in HRS. With the above parameters, the Au/β-Ga2O3/WO3 TF/Ag memristor device has the potential for future RRAM applications. •This article investigates the bipolar resistive switching behavior of bilayer Au/β-Ga2O3/WO3 TF/Ag memristor deposited using an electron beam evaporation technique.•The purity of the deposited sample was confirmed by the XRD and FESEM with EDS characterizations. The surface morphology, roughness, and the chemical bonding of the samples was also investigated by AFM and XPS measurements.•We have observed decrease of bandgap in the heterostructure stack sample from 4.75 eV to 4.35 eV for β-Ga2O3 TF and 3.90 eV to 3.66 eV for WO3 TF which was due to generation of trap states at the heterostructure interfaces.•The Au/β-Ga2O3/WO3 TF/Ag bilayer memristor device attained resistance ratio of ∼ 182, endurance of 300 cycles, and a data retention of 103 s at room temperature. The device also yielded a low SET power of 1.17 mW (at 1.74 mA, +0.67 V) and a low RESET power of 2.50 mW (at 7.16 mA, – 0.35 V).•The transition from the Ohmic conduction in LRS to non-Ohmic conductions in HRS also confirmed the formation and rupture of the conduction path. With the above parameters, the Au/β-Ga2O3/WO3 TF/Ag memristor