Bias tuning charge-releasing leading to negative differential resistance in amorphous gallium oxide/Nb: SrTiO3 heterostructure

Negative differential resistance (NDR) and bipolar resistive switching (RS) phenomena were observed in Au/Ga2O3-x/Nb: SrTiO3/Au heterostructures fabricated by growing amorphous gallium oxide thin films on 0.7% Nb-doped SrTiO3 substrates using pulsed laser deposition technique. The RS behavior is reproducible and stable without the forming process. The NDR phenomenon happened during the course of RS from low resistance state to high resistance state and was dependent much on the applied forward bias. The bias dependent charge releasing from oxygen vacancies was considered to contribute to the NDR behavior. The results show that there is a very close relationship between NDR and RS. (C) 2015 AIP Publishing LLC.