Au doping effects in ZrO 2 -based resistance random access memory based on first-principles calculations

Oxygen vacancy plays the critical role for resistive switching in transition metal oxide resistive random access memory (RRAM). First principles calculation was performed to investigate the band structure, density of states, the oxygen vacancy formation energy and the migration barriers energy of pure ZrO2 and Au doped ZrO2, and we analyzed the impact of Au doping in ZrO2-based RRAM. It was found that the localized impurity band at the Fermi level appeared in forbidden band and the band gap was significantly reduced in Au doped ZrO2, which improved the conductivity of ZrO2. By doping Au in ZrO2, the formation energy and the migration barriers energy of oxygen vacancy were significantly reduced, indicating that it was beneficial to the formation and migration of oxygen vacancy and decreased the forming voltage and the set voltage of ZrO2-based RRAM. The electron localization function was used to study the [001] direction oxygen vacancy cluster of ZrO2 supercell with an Au doped element. The results showed that the oxygen vacancy around the impurity formed an ordered conductive filament in the [001] direction.