Investigation on heteroepitaxy of I-VII compounds and their surface propeties

I-VII化合物的异质外延及其表面性质研究

• 批准号: 07455002
• 负责人: SAIKI Koichiro
• 金额: $ 4.61万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07455002/
• 关键词: Epitaxy; Surface structure; Polar surface; Alkali halide; Cuprous halide; イオン結晶; 分子線エピタキシ-; 表面超構造; 極性表面; 励起子

The results of the present research are summarized.(1)Heteroepitaxy of cuprous halide and their surface propertiesCuprous halide CuX (Ib-VII compounds) belongs to tetrahedrally coordinated binary compounds with zinc blende crystal structure and forms the end points of isoelectronic sequences through IV,III-V,II-VI and I-VII compounds. In this sense CuX is positioned between covalent and ionic materials. We have examined the growth of CuCl, CuBr and CuI on GaAs and Si substrates with various crystal faces and clarified the growth nature. The surface atomic structure differs between crystal faces just like Si and GaAs. However, the dangling bond on CuX surfaces is less active than that of Si and GaAs.(2)Growth of a polar NaCl (111) surfaceA (111) surface of rocksalt crystals is a polar surface consisting of either cations or anions and is expected to show very peculiar surface properties. Up to now such a surface was obtained only by oxidizing a metal surface and was stable for films wit … More h several layrs. We have stabilized a flat NaCl (111) surface by growing such complicated haterostructure as NaCl/CuCl/CuBr/GaAs (111) with use of molecular beam epitaxy. There exist about half layr copper atoms on the (111) surface, which might cancel the macroscopic electric field arising from accumulation of dipole layrs along the [111] direction. The present result opens a way to form a polar surface of another materials such as metal oxides, which might achieve a novel surface in the field of catalysis, low dimensional physics and so on.(3)In-situ optical measurement of alkali halide ultrathin filmsGrowth mode of alkali halide (Ia-VII compounds) on foreign alkali halide substrates has been classified to three types by our previous experiments. That information was obtained by presise RHEED measurement. We have devised a new experimental apparatus consisting of a growth chamber and an optics chamber, where optical absorption measurement could be done in UHV condition for the grown film without breaking vacuum. Use of this system enables the measurement of an ultrathin film with nm thickness. We have investigated the exciton energy for alkali halide thin films, which were grown heteroepitaxially on foreign alkali halide substrates. From the peak energy shift, we could calculate the strain at the interface, which agrees well with the value estimated from the RHEED measurement. Less

总结了目前的研究结果。卤化亚铜CuX（Ib-VII化合物）属于四面体配位的二元化合物，具有锌双金属晶体结构，通过IV、III-V、II-VI和I-VII化合物形成等电子序列的端点。在这个意义上，CuX位于共价和离子材料之间。我们研究了CuCl、CuBr和CuI在不同晶面的GaAs和Si衬底上的生长，阐明了生长的本质。表面原子结构在晶面之间不同，就像Si和GaAs一样。然而，CuX表面上的悬挂键的活性低于Si和GaAs。（2）极性NaCl（111）面的生长岩盐晶体的（111）面是由阳离子或阴离子组成的极性面，具有特殊的表面性质。到目前为止，这样的表面只能通过氧化金属表面获得，并且对于具有以下性质的膜是稳定的： ...更多信息 h几层。我们用分子束外延技术生长了NaCl/CuCl/CuBr/GaAs（111）等复杂异质结构，稳定了NaCl（111）表面。在（111）面上存在约半层的铜原子，这可能会抵消由沿着[111]方向的偶极层积累所产生的宏观电场。这一结果为金属氧化物等其他材料的极性表面的形成开辟了一条新的途径，有望在催化、低维物理等领域获得新的表面。（3）碱金属卤化物薄膜的原位光学测量通过我们以前的实验，将碱金属卤化物（Ⅰ a-VII化合物）在国外碱金属卤化物衬底上的生长模式分为三种类型。这些信息是通过精密RHEED测量获得的。我们设计了一种由生长室和光学室组成的新的实验装置，可以在不破坏真空的情况下在超高真空条件下对生长的薄膜进行光吸收测量。该系统的使用使得能够测量具有nm厚度的薄膜。我们研究了异质外延生长在不同碱金属卤化物衬底上的碱金属卤化物薄膜的激子能量。从峰值能量位移，我们可以计算出在界面处的应变，这与从RHEED测量估计的值吻合得很好。少

项目成果

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T.Shimada 等人：“金属酞菁在 Si(111) 氢端接邻表面上的外延生长”应用物理快报。

N.NISHIDA,K.SAIKI and A.KOMA: ""Heteroepitaxy of CuCl on GaAs and Si substrates"" Surface Science. 324. 149-158 (1995)

N.NISHIDA、K.SAIKI 和 A.KOMA：““GaAs 和 Si 基板上的 CuCl 异质外延””表面科学。

T.Ueno et al.: "Van der Waals epitaxy of metal dihalide" Applied Surface Science. 113/114. 33-37 (1997)

T.Ueno 等人：“金属二卤化物的范德华外延”应用表面科学。

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Y.Fujikawa 等人：“C60 和 C70 超薄膜上的高分辨率电子能量损失光谱”表面科学。