Effect of the coexistence of active metals and boron vacancies on the performance of 2D hexagonal boron nitride resistance memory

First-principles calculations were carried out to calculate the formation energy, migration barrier and electronic properties of a resistive memory model based on hexagonal boron nitride (h-BN) in the presence of an active metal and a boron vacancy (V B ) using density functional theory (DFT). Following the benchmark of the exchange correlation functional and the calculated parameters of monolayer h-BN, a model of a multilayer h-BN vertical stack with distribution states of SW-5577 defects was proposed. For four active metal dopants (Ti, Ag, Cu and Ni), a preference towards substitution sites (S1) with the lowest dopant formation energies (DFEs) was identified, which enhanced the formation of adjacent V B , especially for the nearest neighbour. Furthermore, a low concentration of Ti dopant in the closest location to the initial position of the migration path would drastically reduce the migration barrier of the V B between layers. Finally, Ti dopants with two and three V B neighbours in the same layer significantly improved the conductivity and the formation of conducting channels because of the improvement of charge distribution in the resistance model, which was demonstrated by DOS plots, band-decomposed charge density and Bader charge. Our present work can provide theoretical guidance for the rational design and device optimization of h-BN-based RRAM devices. • A multilayer vertical stack with SW-5577 defects was proposed for theoretical calculation of h-BN based RRAM. • A preference towards substitution site (S1) with the lowest DFEs was identified for Ti, Ag, Cu and Ni dopants. • The closest Ti dopant to the initial position would drastically reduce the migration barrier of the V B between layers. • The increase in the number and spatial distribution of V B is beneficial to the surrounding electron localization.