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HL: Fachverband Halbleiterphysik

HL 17: 2D Semiconductors and van der Waals Heterostructures III

HL 17.4: Vortrag

Dienstag, 18. März 2025, 10:15–10:30, H15

Defect engineering in two-dimensional materials for resistive switching — •Manoj Dey, Matthias Scheffler, and Wahib Aggoune — The NOMAD Laboratory at the FHI of the Max-Planck-Gesellschaft, Berlin, Germany

Non-volatile resistive switching (RS) in memristors has attracted significant attention for advancing in-memory technologies. Recently, exceptional RS has been observed in defected two-dimensional (2D) materials, called atomristors. Adsorption/desorption of metal atoms from the electrodes onto vacancy sites is experimentally observed and proposed as its origin [1,2]. Here, we explore the characteristics of defects and demonstrate their relationship with the observed RS. Using hybrid density functional theory with many body van der Waals corrections, we reveal that the defective monolayers are semiconducting (i.e., high resistivity), whereas adsorption of metal atoms leads to a metallic character (i.e., low resistivity). Interestingly, the adsorption energy of metal is found to be exothermic, with magnitude varying depending on the host materials. This indicates the feasible adsorption and switching in experiments. To bridge with experiments we also consider both the effects of the electrode (e.g. Au(111)) and finite-temperature vibrations. While vibrational effects are negligible, electrode screening induces band gap renormalization and slightly stabilizes metal adsorption compared to free-standing monolayers. These insights will guide the exploration of novel 2D materials for RS applications.

[1] Ruijing Ge et al., Adv. Mater., 33, 2007792 (2021).

[2] Saban M. Hus et al., Nat. Nanotechnol., 16, 58 (2021).

Keywords: 2D materials; Memristor; Density functional theory