叠层复合材料中磁场对半导体输运性质的调控

With the rapid development of the electronic information technology, integration and multi-functionalization of electronic devices are in urgent demanded. The devices coupling magnetism and semiconductors, such as transistors in which the magnetic field tunes the carrier transport of semiconductor, have important application in state-of-the-art electronics. However，it is difficult to realize strong coupling between magnetism and semiconductors in single phase materials at room temperature. Preparing composite materials is an alternative way to realize multi-field coupling. For example, magnetoelectric composites not only have ferromagnetism and ferroelectricity, but also have room temperature magnetoelectric effect by interface strain coupling between ferromagnetic and ferroelectric materials. Recently, two-dimensional transition metal dichalcogenides such as MoS2, WSe2, have gained extensive concerning due to their unique electronics and photoelectronics properties. In this research proposal, through interfacial strain transition and interface piezoelectric charge turning carrier concentration, a series of new types of multifunctional component, and realization of magnetic field modulating transport of the two-dimensional semiconductor materials could be realized by coupling magnetostrictive materials, piezoelectric materials and two-dimensional transition metal dichalcogenides at room temperature. The coupling mechanism between different layers of materials, the regularity and mechanism of the change of semiconductor I-V characteristics with the applied magnetic field will be systematically studied. This research provides a new idea for the design of novel multi-functional electronic devices.

随着电子信息技术的快速发展，对电子器件在集成化和多功能化上提出了更高的要求。例如磁场调制半导体内载流子输运的晶体管，这种耦合磁场和半导体特性的器件在现代电子学领域有着重要的应用。然而室温下在单相材料中很难实现磁性和半导体特性的强耦合，所以制备复合材料是一种变通的实现多性能耦合的方法。例如磁电复合材料不但同时具有铁电性和铁磁性，还可通过铁磁材料和铁电材料的界面应力耦合实现磁电效应。最近，二维过渡金属硫族化合物（如MoS2、WSe2）优异的电子学和光电子学性能引起了人们的广泛关注。本课题研究内容是将磁致伸缩材料、铁电材料和二维过渡金属硫族化合物复合，利用界面应力传递和界面压电电荷对载流子浓度的调控，制备一系列新型多功能复合器件，实现磁场对二维半导体材料输运的调制。同时系统研究了各层材料间的耦合机制、半导体I-V特性随磁场的变化规律和机理。该研究为新型多功能电子器件的设计提供了新的思路。

我们很好的完成了项目的预期研究目标，具体如下：系统研究了二维压电/铁电半导体材料与器件的制备，研究了这些二维压电半导体材料与基底直接的相互作用以及通过基底设计实现应力固化进二维压电半导体材料中。系统研究了基于这一类器件的力-光-半导体耦合性质。基于MoS2-铁电薄膜设计的记忆单元的整合电路可实现光控逻辑运算。该光忆阻系统拓展了忆阻器的定义，是一种新型的数据存储单元，在未来光子存储和运算领域具有潜在应用价值。通过三维应力固化（3D stress stabilization）工艺向二维MoS2中精准且可控地构筑应变梯度，实现永久极化，可以显著提高半导体的载流子迁移率/光响应度，而且可以突破传统机电调控的应用局限性。制备出新型磁调控半导体输运复合材料器件，该器件可以在外加磁场的作用下有效调节半导体内载流子浓度，具体表现在磁场作用下该器件的源漏电流发生变化。揭示磁调控半导体复合材料器件中的磁-力-电-半导体之间的耦合机制，并在此基础上设计和开发出一系列新型多功能器件。其中磁场调控的场效应晶体管在在外加磁场作用下显示出高灵敏度，磁场开/关比为17，规范因子为2.3×104，其变化率远超巨磁阻和隧穿磁阻的变化率。本项目的支持下发表高水平sci论文34篇，授权专利3项。