An Ultrafast Nonvolatile Memory with Low Operation Voltage for High‐Speed and Low‐Power Applications

Abstract

Memory plays a vital role in modern information society. High‐speed and low‐power nonvolatile memory is urgently demanded in the era of big data. However, ultrafast nonvolatile memory with nanosecond‐timescale operation speed and long‐term retention is still unavailable. Herein, an ultrafast nonvolatile memory based on van der Waals heterostructure is proposed, where a charge‐trapping material, graphdiyne (GDY), serves as the charge‐trapping layer. With the band‐engineered heterostructure and excellent charge‐trapping capability of GDY, charges are directly injected into the GDY layer and are persistently captured by the trapping sites in GDY, which result in an ultrafast writing speed (8 ns), a low operation voltage (30 mV), and a long retention time (over 104 s). Moreover, a high on/off ratio of 106 is demonstrated by this memory, which enables the achievement of multibit storage with 6 discrete storage levels. This device fills the blank of ultrafast nonvolatile memory technology, which makes it a promising candidate for next‐generation high‐speed and low‐power‐consumption nonvolatile memory.

Low-voltage ultrafast nonvolatile memory via direct charge injection through a threshold resistive-switching layer

“…Supplementary Table 1 summarizes the parameters of the reported nonvolatile memory devices based on 2D vdWs heterostructures 6 , 8 – 10 , 18 – 21 , 25 , 27 , 28 , 34 – 46 , and Fig. 3h, i compares the operation speed, retention time, and operation voltage of these devices.…”

“…For example, a semi-floating-gate memory with quasi-nonvolatile behavior was proposed 6 , 9 , 20 , in which charges can be directly injected into the floating gate through a p-n junction instead of the FN tunneling, and thus it features an operation voltage of a few volts. Recently, we developed an asymmetric ultrafast nonvolatile memory based on direct-charge-injection mechanism, featuring ultrahigh speed (8 ns) and ultralow voltage (30 mV) in the writing operation 21 . Although these devices still feature some significant deficiencies, e.g., limited retention time and slow erasing speed, it provides a possible strategy to develop low-voltage ultrafast nonvolatile memory beyond the FN tunneling mechanism.…”

2D Heterostructures for Ubiquitous Electronics and Optoelectronics: Principles, Opportunities, and Challenges

“…2D heterostructures can supply possibilities for the design of new electronic memories. ,,− ,,,,, Table exhibits representative 2D heterostructure-based memories. ,− It is representative of three types of 2D heterostructure-based electronic memories: floating gate memory, ORAM, and large-scale 3D memory (Figure c). ,,, Since we thoroughly discussed optical memory circuits in ORAM in the previous section, here we mainly focus on nonoptical-based memory systems.…”

Ultrafast flash memory with large self-rectifying ratio based on atomically thin MoS2-channel transistor

“…The most attractive features of 2D materials are the dangling bonds that are free on their surfaces, their atomic crystallinity in a single layer, and their ability to be adhered to one another by the van der Waals force [5][6][7], offering an attractive platform for novel 2D electronic devices on the atomic scale. Accordingly, many successful attempts have been made to use 2D materials and their heterostructures to improve memory performance [8][9][10][11][12][13][14][15][16]. For example, the van der Waals MoS 2 /h-BN/multilayer graphene (MLG) heterostructure [13] and van der Waals InSe/h-BN/MLG heterostructure [14] based flash memory have been proven to enable a 20 ns programming/erasing speed.…”