posted on 2024-01-16, 14:46authored bySung Jin Yang, Liangbo Liang, Yoonseok Lee, Yuqian Gu, Jameela Fatheema, Shanmukh Kutagulla, Dahyeon Kim, Myungsoo Kim, Sungjun Kim, Deji Akinwande
Recently, we demonstrated the nonvolatile resistive switching
effects
of metal–insulator–metal (MIM) atomristor structures
based on two-dimensional (2D) monolayers. However, there are many
remaining combinations between 2D monolayers and metal electrodes;
hence, there is a need to further explore 2D resistance switching
devices from material selections to future perspectives. This study
investigated the volatile and nonvolatile switching coexistence of
monolayer hexagonal boron nitride (h-BN) atomristors using top and
bottom silver (Ag) metal electrodes. Utilizing an h-BN monolayer and
Ag electrodes, we found that the transition between volatile and nonvolatile
switching is attributed to the thickness/stiffness of chain-like conductive
bridges between h-BN and Ag surfaces based on the current compliance
and atomristor area. Computations indicate a “weak”
bridge is responsible for volatile switching, while a “strong”
bridge is formed for nonvolatile switching. The current compliance
determines the number of Ag atoms that undergo dissociation at the
electrode, while the atomristor area determines the degree of electric
field localization that forms more stable conductive bridges. The
findings of this study suggest that the h-BN atomristor using Ag electrodes
shows promise as a potential solution to integrate both volatile neurons
and nonvolatile synapses in a single neuromorphic crossbar array structure
through electrical and dimensional designs.