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.

这项研究的目的是证明发光特性起源于氟化钙（CAF_2）中形成的纳米尺寸晶体，该晶体是在硅底物上生长的宽带间隙离子材料。在这种材料系统中，由于杂气接口处的较大的导带不连续性，可以预期强大的量子限制，从而导致了来自大块物质的电子光子相互作用的引人入胜的变化。在本研究中获得的结果如下。分子束外延的Caf_2再生。优化了生长温度，背景压力，RF功率和退火后。II）在380 nm的波长下超紫罗莱氏光致发光，并在室温下观察到电致发光。透射电子显微镜（TEM）晶格图像清楚地证实了CAF_2/ZnO/CAF_2的尖锐异质面。发光强度和表面形态优化了生长条件。III）引入了氧气或超高真空中的热退火过程，以改善发光强度。发光对退火温度，时间，压力的依赖性。IV）使用电流限制结构证明了电流注射发光，并使用光刻和干燥蚀刻的透明导电ITO电极进行了透明导电ITO电极。在室温下清楚地观察到了紫外发光，并且发光稳定。从这个结果，嵌入在单晶CAF_2中的纳米晶体ZnO具有稳定的异互面，这对于硅基板上的紫外光子材料具有axtractive。