Vanadium- and Titanium Dioxide-Based Memristors Fabricated via Pulsed Laser Deposition

Investigation of Resistance Switching and Synaptic Properties of VOx for Neuromorphic Applications

“…The most intensive excitation peak at 384 nm can be assigned to the free-excitation emission. ,− The excitation peaks around ∼448 nm may be attributed to the electric charge transfer corresponding to the bonding energy of OV and O–V–O bonds . The emission peaks around 750 nm are related to the transmission of d electrons of Vanadium to the p orbitals holes of Oxygen or may be due to the oxygen vacancies in VO x thin film structures. ,, While the excitation peaks occurred at a narrower wavelength with increasing film thickness, the emission peaks arising from the oxygen vacancy became more prominent with increasing film thickness. As a result, the PL spectrum clearly revealed that oxygen vacancies exist in VO x thin films and these oxygen vacancies tend to increase with increasing film thickness.…”

“…Recent researches indicate that the resistive switching behavior is caused by nanosized conductive filament structures resulting from the mobile oxygen vacancies in the VO 2 structure. 21,22 Recently, memristors based on Mott insulators such as VO 2 have been studied intensively due to the metal−insulator transition being just above room temperature. This reversible phase transition can be controlled by electrical pulses.…”

“… Among these compounds, the Mott insulator VO 2 recently has been intensively studied due to the large conductance changes at room temperature. Recent researches indicate that the resistive switching behavior is caused by nanosized conductive filament structures resulting from the mobile oxygen vacancies in the VO 2 structure. , …”

“…Recent researches indicate that the resistive switching behavior is caused by nanosized conductive filament structures resulting from the mobile oxygen vacancies in the VO 2 structure. 21 , 22 …”

Memory effects and nonlinear electrical conductivity of doped perovskite-like lanthanum-strontium ferrite, La-=SUB=-0.5-=/SUB=-Sr-=SUB=-0.5-=/SUB=-Fe-=SUB=-0.75-=/SUB=-Al-=SUB=-0.2-=/SUB=-Ni-=SUB=-0.05-=/SUB=-O-=SUB=-3-delta-=/SUB=-

“…Memristor effects have already been observed for many metal oxides (TiO 2 , SiO 2 , CuO, NiO, CoO, Fe 2 O 3 , MoO, VO 2 ) and oxide compounds, such as SrTiO 3−δ , (La, Sr)MnO 3 , (Pr, Ca)MnO 3 , BaTiO 3 , (La, Sr)(Co,Fe)O 3 and CeCu 3 Ti 4 O 12 [8][9][10][11][12][13][14][15][16][17][18]. Unfortunately, in most cases, a binary-type memristor effect was observed due to the almost inevitable formation of metal filaments or metal dendrites due to reactions like Me +2 O −2 + V +2 O + 2e ⇔ Me 0 occurring on a growing metal tip due to the drift of mobile oxygen vacancies (V +2 O ).…”