First-principles study of bipolar resistive memories based on monolayer α-GeTe

Yuehua Dai; Bin Yang; Xing Li; Peng Shao; Xiaoqing Wang; Feifei Wang; Cheng Ding; Fei Yang

doi:10.1088/1361-6528/ac1d04

First-principles study of bipolar resistive memories based on monolayer α-GeTe

Nanotechnology. 2021 Aug 31;32(47). doi: 10.1088/1361-6528/ac1d04.

Authors

Yuehua Dai¹, Bin Yang¹, Xing Li¹, Peng Shao¹, Xiaoqing Wang¹, Feifei Wang¹, Cheng Ding¹, Fei Yang¹

Affiliation

¹ School of Electronics and Information Engineering, Anhui University, Hefei 230000, People's Republic of China.

PMID: 34384054
DOI: 10.1088/1361-6528/ac1d04

Abstract

In this work, the electrical properties of monolayerα-GeTe (MLα-GeTe) based on first-principles were studied, in which armchairα-GeTe shows an ohmic current-voltage relationship and zigzagα-GeTe shows an obvious nonlinear current. The potential distribution and band structure explain the mechanism for the anisotropy and nonlinearity. Then, based on calculation of the binding energy and Mulliken population, eight interface structures between graphene (GR) and MLα-GeTe were constructed, in which GC3 and TC3 were found to be relatively stable. Next, GR/MLα-GeTe/GR was established based on the two interfaces (GC3 and TC3). The current-voltage (IV) characteristics were calculated to show that the device has bipolar resistance characteristics, suitable set and reset voltages and a high window value (10⁴). Further analysis of electron density inferred that the resistance mechanism was based on the drift of Te vacancies forming conductive filaments. And the performance of GR/MLα-GeTe/GR was found to be improved by the creation of Te vacancies. This work indicates that GR/MLα-GeTe/GR has the potential to be used to build resistive random access memory (RRAM) with good performance and may be instructive and valuable for the manufacture and application of RRAM.

Keywords: 2D; GeTe; RRAM; bipolar; memories; monolayers; principles.