In-Gap States and Band-Like Transport in Memristive Devices

Abstract

Point defects such as oxygen vacancies cause emergent phenomena such as resistive switching in transition-metal oxides, but their influence on the electron-transport properties is far from being understood. Here, we employ direct mapping of the electronic structure of a memristive device by spectromicroscopy. We find that oxygen vacancies result in in-gap states that we use as input for single-band transport simulations. Because the in-gap states are situated below the Fermi level, they do not contribute to the current directly but impact the shape of the conduction band. Accordingly, we can describe our devices with band-like transport and tunneling across the Schottky barrier at the interface.

Electron Trapping Mechanism in LaAlO3/SrTiO3 Heterostructures

“…Among all types of defects in STO, V O has the lowest activation enthalpy for migration [45] as reported in previous works [46][47][48]. The second step is the clustering of V O 's which could form in-gap trapping states [49,50], of which the energy was recently determined to be ∼0.31 and ∼1.11 eV below the conduction band [51]. Figure 5 shows the dynamic resistance change during and after V G sweeps in the FS irrev and BS regimes.…”

Tuning the Optical Absorption of Anatase Thin Films Across the Visible-To-Near-Infrared Spectral Region

“…The surface properties of titanium dioxide (TiO 2 ) [1][2][3][4] make this system a very widely studied oxide for possible applications in photocatalysis [5,6] and many other fields [7][8][9][10]. An impressive number of real devices based on the photocatalytic properties of TiO 2 are nowadays available, such as devices for photoinduced water photolysis, photocatalytic devices, photocatalytic self-cleaning TiO 2 -coated materials, devices using the photocatalytic antibacterial effect of TiO 2 films, devices using photoinduced hydrophilicity, and many others [5].…”

New insights into the electron trapping mechanism in LaAlO_3 / SrTiO3 heterostructures

“…Electromigration of V O s in STO has been reported in previous works [41][42][43]. The second step is the clustering of V O s. It has been calculated that V O s clustering could form in-gap trapping states [44,45], of which the energy was recently determined to be ∼0.31 eV and ∼1.11 eV below the conduction band [46]. Fig.…”