Ultrafast reconfigurable direct charge trapping devices based on few-layer MoS2

Abstract

Charge trapping devices incorporating 2D materials and high-κ dielectrics have emerged as promising candidates for compact, multifunctional memory devices compatible with silicon-based manufacturing processes. However, traditional charge trapping devices encounter bottlenecks including complex device structure and low operation speed. Here, we demonstrate an ultrafast reconfigurable direct charge trapping device utilizing only a 30 nm-thick Al2O3 trapping layer with a MoS2 channel, where charge traps reside within the Al2O3 bulk confirmed by transfer curves with different gate-voltage sweeping rates and photoluminescence (PL) spectra. The direct charging tapping device shows exceptional memory performance in both three-terminal and two-terminal operation modes characterized by ultrafast three-terminal operation speed (∼300 ns), an extremely low OFF current of 10−14 A, a high ON/OFF current ratio of up to 107, and stable retention and endurance properties. Furthermore, the device with a simple symmetrical structure exhibits VD polarity-dependent reverse rectification behavior in the high resistance state (HRS), with a rectification ratio of 105. Additionally, utilizing the synergistic modulation of the conductance of the MoS2 channel by VD and VG, it achieves gate-tunable reverse rectifier and ternary logic capabilities.