Fig. 3. RS mechanism.
(A) Top-view scanning STEM-ADF (top left) with the corresponding SAED image (top right) and EDS mapping (bottom) of Ag-IPS. The scale bar of the SAED image is 5 1/nm. (B) Micro–UV-visible absorption of the pristine IPS and Ag-IPS. The Ag-IPS has a smaller bandgap than the IPS. (C) Photoluminescence (PL) spectra of IPS and Ag-IPS under a 532-nm laser. (D) Differential charge density distribution of Ag-IPS. The differential charge density is calculated by subtracting the pristine IPS charge density from the Ag-IPS charge density. The lake blue and dusty blue isosurface contours represent the charge accumulation and depletion, respectively. (E) Calculated diffusion energy barriers of Ag migrating through adjacent layers via the structural vacancy (Vint.) and S vacancy (VS1) in the IPS and via charged vacancies around the doped Ag in Ag-IPS. (F) Schematic illustration of the concentrated CF formation in the Ag-IPS memristor.