高迁移率Cd3As2薄膜在III-V族半导体上的分子束外延生长及其磁性掺杂

High electron-mobility materials are the key ingredients of high-speed electronic devices, and its magnetic doping would provide an ideal material playground for the investigation of spintronics. Theoretical and experimental works indicate that Cd3As2 is a topological Dirac semimetal featuring ultra-high carrier mobility, and Cd3As2 is also an ideal material for the study of many novel physical phenomena. For the above reasons, this project aims at the molecular-beam epitaxy (MBE) and magnetic doping of high mobility Cd3As2 films on III-V semiconductors. The MBE growth conditions would be optimized first, followed by its controllable carrier doping. Then magnetic doping will be carried out by low-temperature MBE technique, while co-doping of magnetic transition-metal (TM) and non-magnetic elements be explored subsequently to investigate the possibility of independent manipulation of carrier and spin. Comprehensive characterizations of the carrier density, mobility, magnetoresistance and magnetic behaviors for Cd3As2 and (Cd,TM)3As2 would be performed, in order to establish the relationship between these critical parameters. It is expected that this project would lay a physical and technological foundations for the further research of Cd3As2/III-V semiconductors-based high-speed electronic devices and semiconductor spintronics.

利用高电子迁移率材料可以构建快速响应的电子器件，而对其进行磁性掺杂则为研制自旋电子器件提供了材料基础。理论和实验表明Cd3As2是拓扑Dirac半金属，具有很高的载流子迁移率，且是研究许多新奇物理现象的理想宿主材料。基于此，本项目计划利用分子束外延技术在III-V族半导体上制备高迁移率的Cd3As2薄膜并研究其载流子掺杂，建立生长条件与其晶体结构、载流子类型和迁移率的关系；利用非平衡的低温分子束外延技术制备过渡族元素(TM)掺杂的Cd3As2薄膜并系统研究其磁电性质，掌握磁性元素对Cd3As2物性的影响；通过磁性元素和非磁性元素的共掺杂，研究(Cd,TM)3As2薄膜磁性与载流子类型和浓度的关系，初步探索在(Cd,TM)3As2中实现载流子和自旋独立调控的可能性。本项目期望为深入研究Cd3As2/III-V族半导体基高速电子器件和半导体自旋电子学提供前期物理和材料技术基础。

利用高电子迁移率材料可以构建快速响应的电子器件，而对其进行磁性掺杂则为实现自旋电子器件提供了材料基础。理论和实验表明Cd3As2是拓扑Dirac半金属，具有很高的载流子迁移率，且是研究许多新奇物理现象的理想宿主材料。本项目在2018-2020年三年执行期间，按照基金委重点项目计划书，开展了Cd3As2薄膜分子束外延生长研究，建立了材料生长条件与其晶体结构、载流子类型和迁移率的关系；利用非平衡的低温分子束外延技术制备过渡族元素(TM)掺杂的Cd3As2薄膜并系统研究其磁电性质，掌握了磁性元素对Cd3As2物性的影响；基于场效应晶体管结构，实现了对(Cd,Mn)3As2薄膜量子输运性质的有效电场调控。.项目执行期间共发表相关文章5篇，申请专利1项。项目相关国际会议邀请报告4次，国内会议邀请报告3次。