Amorphous gallium oxide thin film with heavy oxygen deficiency was deposited on Pt/Ti/SiO2/Si substrate by pulsed laser deposition in order to explore the resistive switching behavior of the Pt/Ga2O3-x/Pt sandwich structure. A well unipolar resistive switching behavior was obtained in this structure, which exhibits a high resistance ratio of OFF/ON up to 104, non-overlapping switching voltages, and excellent repeatability and retention. Both I-V relation plots of ON and OFF states and temperature dependent variation resistances indicate that the observed resistive switching behavior can be explained by the formation/rupture of conductive filaments formed out of oxygen vacancies.

We report the transition from bipolar resistive switching (BRS) to unipolar resistive switching (URS) in the Au/ Ti/GaO x /NiO x /ITO device at room temperature. After the proper soft breakdown of the p-n junctions (GaO x /NiO x ), the switching operation could be easily transferred from BRS to URS mode. The BRS and URS behaviors are possibly related to the interfacial variation of the Ti/GaO x Schottky junction barrier and GaO x /NiO x p-n junction barrier, respectively. The high/low resistance state can be distinguished clearly and be switched reversibly under a train of voltage pulses in both BRS and URS modes. The endurance characteristics show good reliability of the stored resistance state. These results suggest a potential device for the next generation of nonvolatile memory applications.

Metal oxide memristors are highly desirable for bionic synaptic applications.

Transmission spectrum and reflectance spectrum have long been used to characterize gap semiconductor. Transmission spectrum can be measured very directly, but the influence of substrate absorption is often unavoidable. However, when using the reflectance spectrum measurement, the absorption of thin film, substrate absorption, and coherent interference will make the reflectance spectrum much more complicated. In this paper, Considering the absorption of thin film, substrate absorption, and coherent interference, we use the envelope curves algorithm to achieve the calculation formula of refractive index deduced from the reflectance spectrum. Through the analysis of the reflectance spectrum of Ga2O3film, we achieved thickness of the film, refractive index, extinction and absorption coefficient and dispersion constant.