"Two-dimensional materials" refer to materials in which electrons can only move freely (planar motion) on the non-nanoscale (1-100nm) in two dimensions, such as nano-films, superlattices, and quantum wells. When these layered two-dimensional materials are stacked together, they will show new electrical, optical, and thermal properties. Therefore, because two-dimensional materials help increase the capacity of electronic devices, the interest in two-dimensional materials in academia and industry has been increasing recently. Among them, graphene is a typical two-dimensional material. Boron oxide

"RRAM" is based on a new type of semiconductor material. Depending on the voltage applied to it, the resistance of the material changes accordingly between a high resistance state and a low resistance state, thereby opening or blocking the current flow channel, allowing or rejecting electrons. The two forms of the flow, correspondingly represent the number "0" or "1", using this property can be made into a memory for storing various information.

In addition, RRAM is also called a memristor. Memristor, the English name "Memristor" is a hybrid word of the English words Memory (memory) and Resistor (resistance). As the name suggests, it is related to memory and resistance. The first person who proposed the concept of memristor was taught in the United States Cai Shaotang, a Chinese scientist at the University of Berkeley, dated 1971. Professor Cai concluded that there should be another component besides resistance, capacitance and inductor, which represents the relationship between electric charge and magnetic flux.

Research Introduction

This innovative research team is led by Dr. Mario Lanza. He is a young talent of the National Thousand Talents Program. He was born in Barcelona, Spain, and is now doing research at Soochow University in China. Currently, he is working on investigating the properties of layered dielectric materials. In his recent paper published in "Advanced Functional Materials", Professor Lanza and colleagues used multilayer hexagonal boron nitride as the dielectric to design a set of resistive random access memory (RRAM). However, this patented device shows that the operating voltage is as low as 0.4 volts, the current switching ratio is as high as 1,000,000, the expected memory time exceeds 10 hours, and the variability of "cycle to cycle" and "device to device" at the same time can be used. Form a free bipolar and threshold type resistance switch (RS). RS is driven by grain boundary drives (GBs) in a polycrystalline hexagonal boron nitride stack, which allows ions to penetrate from adjacent electrodes. The generation of B vacancies will promote this effect, and B vacancies are more abundant in GBs.

This research was carried out in collaboration with Massachusetts Institute of Technology, Stanford University and Harvard University. The results of this research play a vital role in the development of digital electronic devices made of two-dimensional materials.