权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Fundamental study of light emitting devices on silicon substrate using nanocrystalline heterostructures formed in single crystalline insulator

利用单晶绝缘体中形成的纳米晶异质结构在硅衬底上发光器件的基础研究

基本信息

批准号：
11650315
负责人：
WATANABE Masahiro
金额：
$ 2.3万
依托单位：
TOKYO INSTITUTE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

The purpose of this study is to demonstrate light emitting properties originated from nanometer size crystals formed in single crystalline calcium fluoride (CaF_2), which is a wide band gap ionic material grown on silicon substrate. In such kind of material systems, strong quantum confinement can be expected due to large conduction band discontinuity at the heterointerface, which leads fascinating changes of electron photon interaction from the bulk material.Results obtained in this study are as follows.i) Formation technique of nanocrystalline zinc oxide (ZnO) on CaF_2/Si (111) substrate has been developed using RF sputtering followed by regrowth of CaF_2 by molecular beam epitaxy. Growth temperature, background pressure, RF power and post annealing condition was optimized.ii) Ultra-violet photoluminescence at wavelength of 380 nm and electroluminescence was observed at room temperature. Transmission electron microscopy (TEM) lattice image clearly confirmed that sharp heterointerface of CaF_2/ZnO/CaF_2 was formed. Growth condition was optimized by luminescence intensity and surface morphology.iii) Thermal annealing process in oxygen or ultra-high vacuum was introduced for improving luminescence intensity. Dependence of luminescence on annealing temperature, time, pressure was clarified.iv) Current injection luminescence was demonstrated using current restriction structure with transparent conducting ITO electrode fabricated using photolithography and dry etching. UV luminescence was clearly observed at room temperature and the luminescence was stable. From this result, nanocrystalline ZnO embedded in single crystalline CaF_2 has stable heterointerface, which is atractive for UV photonic materials on silicon substrate.

本研究的目的是证实生长在硅衬底上的宽带隙离子材料氟化钙（CaF_2）单晶中形成的纳米尺寸晶体的发光性质。在这种材料系统中，由于异质界面处的大的导带不连续性，可以预期强的量子限制，本论文的主要研究结果如下：（1）采用射频溅射法在CaF_2/Si（111）衬底上制备了纳米氧化锌（ZnO）薄膜，并在此基础上进行了CaF_2/Si（111）衬底的再生长。2分子束外延。优化了生长温度、背景气压、射频功率和退火条件。ii）室温下观察到380 nm的紫外光致发光和电致发光。透射电子显微镜（TEM）的晶格图像清楚地证实了CaF_2/ZnO/CaF_2形成了尖锐的异质界面。通过发光强度和表面形貌优化了生长条件。（3）引入氧气或超高真空热退火工艺，提高了发光强度。研究了退火温度、退火时间、退火压力对发光的影响。iv）采用光刻和干法刻蚀技术制备ITO透明导电电极，利用电流限制结构实现了电流注入发光。在室温下清楚地观察到UV发光，并且发光稳定。这一结果表明，纳米ZnO嵌入到单晶CaF_2中具有稳定的异质界面，这对硅基紫外光子材料的制备具有重要的指导意义。