Study on photo-induced magnetic transition in II-VI diluted magnetic semiconductor quantum wells with a type band allignment

II-VI型稀磁半导体量子阱中光致磁跃迁的研究

基本信息

批准号：
15340096
负责人：
NAKAMURA Arao
金额：
$ 10.69万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15340096/
关键词：
Type II quantum wells Diluted magnetic semiconductors Magnetic exchange interaction Two-dimensional excitons Band off-set Interfaces of quantum wells Scanning tunneling microscopy Anomalus Hall effects 希薄磁性半導体磁性イオン-キャリア交換相互作用磁性イオン-キャ

项目摘要

1. Preparation of p-type ZnSe/BeMnTe quantum well structuresZnSe/N-doped BeMnTe quantum wells and N-doped BeMnTe thin films were grown on GaAs substrates by a molecular beam epitaxy method. The hole carrier density in the range of 10^<18>-10^<19> cm^<-3>, which corresponds to the carrier density necessary for carrier-induced ferrpmagnetism, was obtained at the temperatures between 2 and 300 K.2. Analysis of cross-sectional structure of ZnSe/BeTe quantum well interfacesCarrier lifetimes and overlapping of electron and hole wave functions strongly depend on the interfacial quality, because the recombination between electrons and holes takes place at the interfaces in the quantum wells with a type II band alignment. We investigated sharpness and alloy effects at the interfaces between ZnSe and BeTe layers in the multiple quantum wells using cross-sectional scanning tunneling microscopy and X-ray diffraction measurements. The filled- and empty-state images revealed that Zn-Te and Be-Se bon … More ds exist at the ZnSe/BeTe interface within the range of 2-4 monolayers along the growth direction. The transition layer between the ZnSe layer and the BeTe layer is composed of the BeZnSeTe quaternary alloy corresponding to (ZnTe)_<0.58>(BeSe)_<0.42>.3. Observation of anomalus Hall effects and ferromagnetic transitionWe measured anomalus Hall effects in N-doped Be_<1-x>Mn_xTe (x=0.05 and 0.10), and found that Be_<1-x>Mn_xTe is ferromagentic at the temperature lower than 10 K. Negative magnetoresistance and its hysterisis behavior were observed for the first time for Be_<1-x>Mn_xTe, which confirmed the carrierd-induced ferromagnetism. The observation of the Hall effect with the high magnetic field supported that the observed negative magnetoresistance is due to free carrier generation from bound magnetic polarons by the applied magnetic field.4. Luminescence properties of ZnSe/BeMnTe quatum well structuresWe investigated effects of applied electric and magnetic fields on luminescence properties, and found that the luminescence at the interfaces is enhanced and reduced by the applied-electric field. However, we could not observe a sharp luminescence band in the highly N-doped ZnSe/BeMnTe quantum well because of the interfacial roughness at the heterojunctions. Less

1。p型Znse/bemnte量子井结构/n掺杂的bemnte量子井和n掺杂的bemnte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte thinte。 <18> -10^<19> cm^<-3> en 2和300 k.2。依赖于AI带对齐的电子cuantum之间的界面E重组Zn-Te和Be-be-bon…在Znse/Bete界面上存在更多DS，在2-4的范围内，Zn-Te和Be-be-ben bot be beznseer和bete层之间存在更多的ds。（znte）_ <0.58> _ <0.42>。低于10 k的磁磁性及其滞后诱导的铁磁性在界面上的发光性特性上的结构性和磁场会增强，并通过施加的电场降低