Due to their unique physical structure and properties, two-dimensional materials have been attracting much attention in the field of spintronic devices and showing important application prospects. In order to fully exploit the performance of such materials, it is critical to construct atomic-mass interfaces, which not only contribute to efficient spin injection and transport, but also play a decisive role in improving the magnetoresistive effect and overall performance of the device. By precisely controlling the spin interface quality of the device, the electrical characteristics of the spintronic device can be optimized, so as to effectively promote the development and application of spintronic technology.
Recently, the team of Professor Zhao Qiang and Associate Professor Luo Zhongzhong of Nanjing University of Posts and Telecommunications has cooperated with Professor Song Xiangxiang of the University of Science and Technology of China to develop a solution-free van der Waals magnetic electrode transfer technology, which has been successfully applied to the construction of a variety of high-performance two-dimensional spintronic devices. The study was published in the internationally renowned academic journal Nano Letters under the title "Van der Waals magnetic-electrode transfer for two-dimensional spintronic devices". Associate Professor Luo Zhongzhong of Nanjing University of Posts and Telecommunications is the first author of the paper, and researcher Song Xiangxiang of University of Science and Technology of China, Professor Zhao Qiang and Professor Xu Yong of Nanjing University of Posts and Telecommunications, and Professor Qin Wei of Shandong University are the co-corresponding authors.
Highlights: 1. Multilayer ferromagnetic electrodes are mechanically transferred to various two-dimensional materials to prepare high-performance spintronic devices. The bottom of each electrode is a single layer of graphene, which on the one hand reduces the adhesion between the electrode and the substrate, which is conducive to the detachment of the electrode from the sacrificial substrate, and on the other hand, it can be used as a tunneling layer to optimize the spin injection of the ferromagnetic/semiconductor interface. 2. The atomic-level controllable ferromagnetic/two-dimensional material spin interface has been realized, and the magnetoresistance performance of graphene and MoS2 spin valves constructed based on this has achieved a breakthrough, reaching the highest level of the same type of device structure. At the same time, the process is also suitable for the construction of two-dimensional organic/inorganic heterojunction channels and multi-terminal non-local spin devices. 3. The gate control of spin devices is realized, and the important influence of interface tunneling resistance and spin channel resistance matching on the performance of the device is revealed, which lays a foundation for further realization of high-performance 2D spin devices.
Source: Frontiers of Polymer Science