Fabrication of semiconductor nanostructures assuming enhanced magneto-optical effects and control of their magnetism by irradiation of light

假设增强磁光效应的半导体纳米结构的制造以及通过光照射控制其磁性

• 批准号: 13450004
• 负责人: TAKITA Koki
• 金额: $ 8.38万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13450004/
• 关键词: self-organized dots; lattice mismatch; diluted magnetic semiconductors; photoluminescence; zero-dimensional exciton; 希薄性半導体; 2次元電子系; 量子ドット; スピントロニクス; 磁気発光特性; 磁気輸送特性; マイグレーション

We have fabricated self-organized dots of CdTe and Cd1-xMnxTe on ZnTe(001) surface by molecular beam epitaxy (MBE). In the present research project, we have performed the following two topics. (1) change the confinement energy of electrons and holes due to the barrier layer by growing the dots on the mixed crystal (band-gap engineering) (2) make the structure in which the dot layer and the barrier layer are grown repeatedly (dot superlattice), as the details are described in the following.(1) Band-gap engineering by changing the barrier layerWe have grown self-organized dots of CdTe on the mixed crystals of (Zn, Mg)Te, in place of ZnTe. In the photoluminescence measurement, it was found that the temperature dependence of the luminescence intensity was improved significantly, with the suppression of the thermal quenching of the luminescence, compared to the dots on ZnTe. This is considered to be caused by the enhancement of the confinement of electron-hole pairs due to the increase of t … More he band-gap energy of the barrier layer. In addition, we grew (Cd, Mn)Te dots on (An, Mg)Te layer in the similar method. In the magneto-PL measurement, we observed the red-shift of the exicitonic emission energy due to the gigantic Zeeman splitting, the amount of this red-shift was found to be consistent with the calculation.(2) Dot superlatticeWe have fabricated the superlattice structure in which the Cd(Mn)Te dot layer and ZnTe barrier layer were stacked with several tens of cycles. In the PL measurement, we observed two emission lines, differently from the sample with the dot single layer. It is considered that the higher-energy line originated from the isolated level of the individual dots and the lower-energy line originated from the correlated level between the dots in the neighboring dot layers. This assignment was confirmed from the results of the PL measurement on a series of sample wiath different thickness of the barrier layers, in which the emission energy of the lower-energy line was shifted systematically with the barrier thickness. Less

利用分子束外延技术（MBE）在ZnTe（001）表面制备了CdTe和Cd1-xMnxTe自组织点。在目前的研究项目中，我们进行了以下两个课题。(1)通过在混合晶体上生长点来改变电子和空穴由于势垒层而产生的约束能（带隙工程）(2)形成点层和势垒层反复生长的结构（点超晶格），具体如下。(1)改变势垒层的带隙工程我们在（Zn, Mg）Te混合晶体上生长了自组织的CdTe点，代替了ZnTe。在光致发光测量中发现，与ZnTe上的点相比，发光强度的温度依赖性明显提高，发光的热猝灭得到抑制。这被认为是由于势垒层的带隙能量增加，电子-空穴对的约束增强所致。此外，我们还采用类似的方法在（An, Mg）Te层上生长（Cd, Mn）Te点。在磁致发光测量中，由于巨大的塞曼分裂，我们观察到外场发射能量的红移，这种红移的量与计算一致。(2)点超晶格我们制备了由Cd(Mn)Te点层和ZnTe势垒层以几十个周期堆叠而成的超晶格结构。在PL测量中，我们观察到两条不同于点单层样品的发射线。认为高能线来源于单个点的孤立能级，低能线来源于相邻点层中点之间的相关能级。对一系列不同势垒层厚度样品的PL测量结果证实了这一指派，其中低能线的发射能量随着势垒层厚度的变化而系统地发生了位移。少

项目成果

F.Takano et al.: "Magneto-photoluminescence spectra around ν=1 in magnetic two-dimensional electron gas"Proc.of 15^<th> International Conference on High Magnetic Fields in Semiconductor Physics. (in press). (印刷中).

F.Takano 等人：“磁性二维电子气中 ν=1 附近的磁光致发光光谱”第 15 届半导体物理高磁场国际会议论文集（正在出版）。

Y.Masumoto et al.: "Highest-order optical phonon-mediated relaxation in CdTe/ZnTe quantum dots"Journal of Luminescence. 102-103. 623-628 (2003)

Y.Masumoto 等人：“CdTe/ZnTe 量子点中的最高阶光学声子介导的弛豫”发光杂志。

F.Takano et al.: "Spatial diffusion of excitons in n-type modulation-doped (Cd, Mn)Te/(Cd, Mg)Te single quantum wells under magnetic fields"Applied Physics Letters. 83. 2853-2855 (2003)

F.Takano 等人：“磁场下 n 型调制掺杂 (Cd, Mn)Te/(Cd, Mg)Te 单量子阱中激子的空间扩散”应用物理快报。

F. Takano et al.: "Mangneto-transport of two-dimensional electron system in magnetic semiconductors heterostructure Cd(Mn)Te/(Cd,Mg)Te"Physica B. 298. 407-410 (2001)

F. Takano 等人：“磁性半导体异质结构 Cd(Mn)Te/(Cd,Mg)Te 中二维电子系统的锰电子传输”Physica B. 298. 407-410 (2001)

Magneto-transport properties of p-type Zn_<1-x>Mn_xTe : N grown by MBE

p型Zn_<1-x>Mn_xTe:MBE生长的N的磁输运特性

• 发表时间: 2003
• 期刊: Journal of Superconductivity : Incorporating Novel Magnetism 16
• 作者: S.Kuroda;N.Itoh;Y.Terai;K.Takita;T.Okuno;M.Nomura;Y.Masumoto;Y.Masumoto et al.;A.V.Akimov et al.;K.-T.Nam et al.
• 通讯作者: K.-T.Nam et al.