HPHA Effect on Reversible Resistive Switching of Pt∕Nb-Doped SrTiO[sub 3] Schottky Junction for Nonvolatile Memory Application

Anomalous effect due to oxygen vacancy accumulation below the electrode in bipolar resistance switching Pt/Nb:SrTiO3 cells

“…A negative (positive) voltage attracts (pushes) V o¨t o (away from) the interface, which induces decrease (increase) of the Schottky barrier width. For f8-type, 11,12 electronic models are proposed involving the trapping and detrapping of electrons at immobile V o¨w ithin interface. Each of these models can provide a simple explanation for each rotation direction.…”

Impact of Defect Distribution on Resistive Switching Characteristics of Sr2TiO4 Thin Films

“…A similar switching behavior has been reported in metal/Nb-doped SrTiO 3 single crystal structures without active layer. [23][24][25] Figure 3a is a schematic drawing of switching polarities as functions of Sr 2 TiO 4 layer thickness and growth temperature. Figure 3b corresponds to Figure1b which shows I-V curves of the junction with a 10 nm thick Sr 2 TiO 4 layer where both switching polarities were observed.…”

“…Therefore, the switching mechanism of the '' Figure-8'' polarity may be attributed to trapping/detrapping effects at the interface defect states between Au and Sr 2 TiO 4 , as proposed in SrRuO 3 /Nb-doped SrTiO 3 junction [6] and Pt/Nb-doped SrTiO 3 interface. [23] Another possibility is that all oxygen vacancies migrate out of the Sr 2 TiO 4 layer or are accumulated at the very top layer. [26] It is however not likely, especially at high oxygen vacancy concentration.…”

“…In particular, the possible electron trapping process in Pt/Nb-doped SrTiO 3 switching devices could be significantly improved by annealing under reduced conditions. [23] Furthermore, Sawa [14] recently reported that annealing in oxidized atmosphere greatly suppressed hysteric I-V behavior in SrRuO 3 /Nb-doped SrTiO 3 as well as in Ti/Pr 0.7 Ca 0.3 MnO 3 junctions. These denote that oxygen vacancies play also an important role even on the electron trapping/detrapping processes.…”

Correlated memory resistor in epitaxial NdNiO3 heterostructures with asymmetrical proton concentration

“…In Pt/Nb-doped SrTiO 3 , the origin of the resistive switching mechanism has long been debated and various models have been proposed, such as charge trapping/detrapping of charge carriers at the interface states 30,31 and modification of electronic structures at the interface as a consequence of electro-migration of oxygen ions (or vacancies). 32,33 Although numerous mechanisms to explain the resistive switching in Pt/Nb-doped SrTiO 3 systems have been suggested, the consensus is that oxygen vacancies (or interface states induced by oxygenrelated defects) contribute to the change of resistance. Due to the migration of negative ions, this interface-type resistive switching shows counter-clockwise sweep when voltage bias is applied to the top electrodes near the highly insulating depletion layer; Unlike other memristors, the opposite response occurs in our asymmetrical devices, so that oxygen-related defects are unlikely to be the origin of our resistive switching.…”