Optical Properties of Thin Alkali-Halide Crystals Prepared by Reacted Epitaxial Method.

反应外延法制备的薄碱卤化物晶体的光学性质。

• 批准号: 05640392
• 负责人: OHNO Nobuhito
• 金额: $ 0.96万
• 依托单位: Faculty of Engineering, Osaka Electro-Communication University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05640392/
• 关键词: Epitaxial Growth; Thin Crystal; Alkali Halides; Optical Property

The recent development of the molecular beam epitaxy (MBE) technique makes it possible to produce sophisticated heterostructures. In the course of this development epitaxial condition for semiconductor materials have been well clarified and plenty of know-how has been accumulated. Compared with this, the epitaxial growth of insulators has been rather little studied so far. In the present study, we have studied the heteroepitaxial growth of KI on alkali halide substrate by using reacted epitaxial method. Optical properties of thin KI films obtained have been investigated in situ during the growth of KI films.At first stage, HI gas was evaporated on a KCl (001) substrate crystal at low temperature (-10K). Next, the temperature of the substrate was increased slowly. Transmission spectra near the absorption edge of KI were monitored in situ with increasing temperature. As a result KI film crystal was found to grow at temperatures of 180-220K in-10A to-100A thickness. It is also found that the film thickness can be controlled depending on the amount of HI gas evaporation.In order to characterize the quality of the films, we have examined the exciton absorption spectra and the luminescence spectra at 10K systematically without exposure to the atmosphere. By comparison with the previous results from the MBE method, the peak energy and the linewidth of the first exciton band of KI films were the almost the same ones as the MBE Films, and were continuously changed to those of a bulk crystal. These facts suggest that the thin films obtained in the present study posses a good quality as that from the MBE method and the lattice relaxation is limited very near to the interface of the substrate. Heteroepitaxial growth of other systems by this reacted epitaxial method are in progress and will be reported in the near future.

分子束外延（MBE）技术的最新发展使制造复杂异质结构成为可能。在这一发展过程中，半导体材料的外延条件得到了很好的阐明，积累了大量的技术知识。与此相比，迄今为止对绝缘体外延生长的研究还很少。本研究采用反应外延法研究了KI在碱卤化物衬底上的异质外延生长。在KI薄膜生长过程中，对KI薄膜的光学性质进行了原位研究。在第一阶段，HI气体在低温（-10K）下在KCl（001）衬底晶体上蒸发。接下来，衬底温度缓慢升高。随着温度的升高，对KI吸收边附近的透射光谱进行了原位监测。结果发现KI薄膜晶体在180-220K的温度下生长，厚度为10a至100a。还发现薄膜厚度可以根据HI气体的蒸发量来控制。为了表征薄膜的质量，我们在不暴露于大气的情况下系统地检测了10K下的激子吸收光谱和发光光谱。与MBE方法的结果比较，KI薄膜的第一激子带的峰能和线宽与MBE薄膜基本相同，并不断地向体晶体转变。这些事实表明，本研究获得的薄膜具有与MBE方法相同的良好质量，并且晶格弛豫被限制在衬底界面附近。其他异质外延生长系统的反应外延法正在进行中，并将在不久的将来报道。

项目成果

M.Inaba: "Optical Study of Phase Separation in Alkali Halide Solid Solution" 7th Europhysical Conference on defects in insulating materials. (印刷中). (1995)

M.Inaba：“碱金属卤化物固溶体中相分离的光学研究”，第七届欧洲物理学会绝缘材料缺陷（正在出版）。

M.Inaba: "Optical study of phase separation in alkali halide solid solution" Proc.7th Europhysical Conference on defects in insulating materials. (in press).

M.Inaba：“碱金属卤化物固溶体中相分离的光学研究”Proc.7th Europhysical Conference 关于绝缘材料缺陷的会议。