Exploring the Feasibility of Monoclinic-ZrO2-Based Memristors As Artificial Olfactory Sensors: an Atomistic Simulation Approach

Memory devices with sensitivity, selectivity, and operation voltage towards the gases are rarely reported for artificial olfactory sensors. Additionally, there are no reports available on the atomistic aspects of artificial olfactory sensors. This study reports an atomistic simulation of monoclinic-ZrO2 (m-ZrO2). The impact of external electric field on the formation of the oxygen vacancies are evaluated by considering the different directions of electric field. Furthermore, it is conducted nudged elastic band calculations which showed a decrease in the migration barrier energy with an increase in the electric field for all considered directions. Moreover, it is simulated the memristor device (Ta/m-ZrO2/Pt) and investigated the impact of oxygen vacancies on electrical conductivity by considering oxygen vacancies at different locations in m-ZrO2. Finally, it is evaluated the possibility of using the m-ZrO2 based memristor device for an artificial olfactory sensor by studying the gas sensing properties of the (111) surface of m-ZrO2. The pristine structure exhibits low sensitivity towards toxic molecules (CO2, CO, NH2, and NO2), while the sensing performance is significantly enhanced on the oxygen vacancy rich surface. These atomistic simulation results provide an atomic level understanding of the Ta/m-ZrO2/Pt device and suggest the potential for it to be use as an artificial olfactory sensor.