Multi-scale modeling of oxygen vacancies assisted charge transport in sub-stoichiometric TiOx for RRAM application

In this work we investigate the charge transport in sub-stoichiometric TiOx for RRAM applications. We explored the atomic defect configurations actively assisting the charge transport in sub-stoichiometric TiOx through a multi-scale approach. We combined density-functional-theory-based non-equilibrium Green´s function approach (DFT_NEGF) with physical-based trap assisted tunneling (TAT) modeling to identify the defects dominating the current conduction mechanism and the physical parameters of the defects responsible for the trap-assisted tunneling (TAT). The values of the thermal ionization energy E_T and relaxation energy E_REL extracted are 0.35-0.4eV and 0.7eV, respectively.