Partially Oxidized MXene Ti₃C₂T_x Sheets for Memristor having Synapse and Threshold Resistive Switching Characteristics

Abstract

Transition metal carbides, called MXenes, can be used for MXene‐based unique electronic devices such as new types of batteries, energy storage devices, and supercapacitors, where MXene is used as an electrode. The unique surface properties of MXene and 2D structure can be further applied to the new electronic devices. In this paper, the unique insulating properties of partially oxidized MXene (Ti3C2Tx) sheets are utilized for memory storage and electronic synapse applications. The device exhibits threshold resistive switching characteristics based on Ag+ migration dynamics. It is found that this Ag+ cation migration is similar to Ca2+ ion dynamics of a biological synapse, and thus, biological synapse functions such as intrusion/extrusion of Ag+ cation, paired‐pulse facilitation (PPF), post‐tetanic potentiation (PTP), short‐term potentiation (STP), and transition of STP to long‐term potentiation (LTP) are well‐emulated. It is believed that this device development can be potentially used in the next‐generation hardware‐based artificial intelligence systems.

Tunable Volatile to Non‐Volatile Resistive Switching in PbZrO3 Antiferroelectric Thin Film for Neuromorphic Computing

“…Remarkably, the current response signal is very similar to the single impulse response previously found in Ag/Ti 3 C 2 T x NS/Pt structure, the fast relaxation in Ag/Ti 3 C 2 T x NS/Pt is corresponding to the high electronegativity of MXene thin film with a large amount of ‐F/‐O functional groups. [ 53 ] This similar phenomenon may be due to the fast transition between AFE–FE phases and polarization reorientation. After the spike voltage removed, the device transforms to initial state which is corresponding to the disordered polarization state under low electric field.…”

“…PPF is an important short-term memory property of biological synapse. [9,[53][54][55] It is a phenomenon in which the presynapse is repeatedly stimulated twice at a short interval, and the synaptic response induced by the second stimulus is greater than that of the first stimulus. The PPF property of Pt/PZO/ LNO/STO device is shown in Figure 7b with 1 ms duration and 1 ms interval 5 V pulse voltage, the PPF rate can reach to 175% in this condition.…”

Surface engineering of MXenes for energy and environmental applications

“…For example, partially oxidized Ti 3 C 2 T x sheets obtained by etching Ti 3 AlC 2 at higher temperature (65 °C) can be used for memristors with synapse and threshold resistive switching characteristics. 194 A small quantity of TiO 2 particles was produced in the partially oxidized Ti 3 C 2 T x sheet, and these TiO 2 particles hampered the connections of Ti 3 C 2 T x sheets, and hence the conductivity was very close to that of an insulator. In addition, the partially oxidized Ti 3 C 2 T x sheets cannot exhibit compact restacking with the TiO 2 particles on the surface acting as the spacer, and such spaces can provide a path for silver migration during the threshold switching.…”

Conductive Bridge Random Access Memory (CBRAM): Challenges and Opportunities for Memory and Neuromorphic Computing Applications

“…The switching materials are classified into two categories: metal oxides [ 17 , 18 , 19 , 20 ] and non-oxides. The non-oxides are further classified as chalcogenides [ 21 , 22 , 23 ], 2D materials [ 24 , 25 , 26 , 27 ], organic materials [ 28 , 29 ] and other emerging materials [ 30 , 31 , 32 ].…”