Resistive Switching in Few-Layer Hexagonal Boron Nitride Mediated by Defects and Interfacial Charge Transfer
Hokyeong Jeong, Jiye Kim, Jiye Kim, Dong Yeong Kim, Jaewon Kim, Jaewon Kim, Seokho Moon, Odongo Francis Ngome Okello, Sangmin Lee, Hyunsang Hwang, Si‐Young Choi, Jong Kyu Kim, Jong Kyu Kim
Abstract
We present resistive switching (RS) behavior of few-layer hexagonal boron nitride (h-BN) mediated by defects and interfacial charge transfer. Few-layer h-BN is grown by metal–organic chemical vapor deposition and used as active RS medium in Ti/h-BN/Au structure, exhibiting clear bipolar RS behavior and fast switching characteristics about ∼25 ns without an initial electroforming process. Systematic investigation on microstructural and chemical characteristics of the h-BN reveals that there are structural defects such as homoelemental B–B bonds at grain boundaries and nitrogen vacancies, which can provide preferential pathways for the penetration of Tix+ ions through the h-BN film. In addition, the interfacial charge transfer from Ti to the h-BN is observed by in situ X-ray photoelectron spectroscopy. We suggest that the attractive Coulomb interaction between positively charged Tix+ ions and the negatively charged h-BN surface as a result of the interfacial charge transfer facilitates the migration of Tix+ ions at the Ti/h-BN interface, leading to the facile formation of conductive filaments. We believe that these findings can improve our understanding of the fundamental mechanisms involved in RS behavior of h-BN and contribute a significant step for the future development of h-BN-based nonvolatile memory applications.