Fabrication of Spin Controlled Semiconductor Superstructures

该研究组的主要任务是制备含有磁性离子的III-V族和II-VI族稀磁半导体和硅体系的新超结构，研究其量子磁光性质、化学物种依赖性、磁性和输运性质、自旋动力学，并建立其基础理论。为此，设计和制备了各种半导体超结构，并探索了新的磁性和磁光功能。对这些新性质进行了理论研究.稀磁半导体量子纳米结构的制备及磁光研究制备了稀磁半导体CdMnTe和CdMnSe的新量子纳米结构，并研究了它们的磁光性质和应用。利用超快时间分辨光致发光技术研究了这些量子威尔斯阱、量子线和量子点中电子和激子的磁光效应和自旋动力学 ...更多信息 scence光谱和泵和探测瞬态吸收光谱。发现了新的磁光性质，如双稀磁量子威尔斯阱中激子隧穿、量子点中激子非辐射过程的磁抑制和激子超快自旋弛豫过程。2. Ⅲ-Ⅴ族稀磁半导体的电子和磁性的载流子浓度依赖性和化学趋势（Ga，Mn）As的研究采用了施主和受主掺入法。在（Ga，Mn）As中引入Sn施主，掺杂量达到5%，n型掺杂证实了控制（Ga，Mn）As 3空穴浓度的可能性。重掺杂磁性杂质的Si基稀磁半导体超结构的生长和性能研究采用激光烧蚀和光激发CVD方法制备了Si基稀磁半导体。获得了高浓度Mn的Si膜。第一性原理计算表明，Si：Mn系统中可能存在类似于（Ga，Mn）As的铁磁性.基于稀磁III-V族半导体的混合超结构研究了（In，Mn）As/（Ga，Al）Sb异质结构在光照下的载流子感生磁性。结果表明，非磁性和磁性半导体层之间的相互作用的重要性。用铁离子制备Ⅲ-Ⅴ族稀磁半导体也取得了一些进展

The group was organized to fabricate new superstructures of III-V and II-Vl diluted magnetic semiconductors and silicon system involving magnetic ions and to study the quantum magneto-optical properties, chemical-species dependence, magnetism and transport properties, spin dynamics and also to establish their basic theories. For these purposes, designing and fabrication of various semiconductor superstructures were made and explored the new magnetism and magneto-optical functionarities. Theoretical investigation of these new properties was also carried out.1. Fabrication and magneto-optical study of quantum nanostructures of diluted magnetic semiconductors New quantum nanostructures of diluted magnetic semiconductors CdMnTe and CdMnSe were fabricated and their magneto-optical properties and applications were studied. The magneto-optical effects and the spin dynamics of electrons and excitons were studied in these quantum wells, wires, and dots by the ultrafast time resolved photolumine … More scence spectroscopy and the pump-and probe transient absorption spectroscopy. New magneto-optical properties were found such as the exciton tunneling in double diluted magnetic quantum wells, the magnetic suppression of the non-radiative process of excitons in the quantum dots and the ultrafast spin relaxation processes of excitons.2.Carrier concentration dependence and chemical trend of electronic and magnetic properties on III-V diluted magnetic semiconductors Carrier concentration control of (Ga, Mn)As was investigated by incorporation of donor and acceptor. Sn-donors were introduced to (Ga, Mu)As up to 5% and the n-type doping demonstrated the possibility of the control of the hole concentration of (Ga, Mn)As3.Growth and properties of silicon-related superstructures doped heavily with magnetic impurities Si-based diluted magnetic semiconductors were fabricated by laser ablation and photo-excited CVD methods. Si films with high concentration of Mn were obtained. A first principle calculation was performed-to indicate that the ferromagnetism similar to that in (Ga, Mn)As is possible in Si : Mn systems.4. Hybrid superstructures based on diluted magnetic III-V semiconductors The carrier induced magnetism with a light irradiation on the (In, Mn)As/(Ga, Al)Sb heterostructures was studied. The results demonstrated the importance of interplay between non-magnetic and magnetic semiconductor layers. Preparation of III-V diluted magnetic semiconductors with Fe ions was also develnned Less