Atomically-controlled growth and properties of low-dimensional lanthanoide/semiconductor quantum structures

人们对稀土元素与III-V半导体的结合越来越感兴趣。其中一个原因是稀土与v族元素反应形成镧系元素，如ErP和ErAs。在半导体异质结构中加入镧系元素层有望促进量子限制系统和新型电子器件中的新物理，因为镧系元素表现出半金属行为。在这个研究项目中，我们研究了ErP在InP衬底上的自动控制超级定位。实验结果总结如下：1)发现了适宜ErP生长的Er源。在使用Er(DPM)_3，三二戊基甲烷铒时，沉积物不含Er原子，但暴露于Er源后表面形貌发生了剧烈变化。2)采用选择性面积生长技术，在不同取向的InP表面（001）、（011）、（111）A和（111）B上生长ErP。在（111）B表面成功获得了较大的ErP岛，岛顶相对平坦。3)在（111）B InP衬底上生长出InP/ErP/InP双异质结构。与（001）衬底上的结构相反，在ErP层上成功地以逐层模式生长了InP帽层。4)对于晶格匹配良好的DyP/GaAs结构，在初始阶段进行了Dy掺杂到III-V半导体中。以三甲基环戊二烯镝Dy(MeCp)_3为原料，在GaAs和InP中实现了可控的Dy掺杂。在掺镝的砷化镓中，首次观察到四个波长区域的特征Dy发光。

There has been increasing interest in the combination of rare-earth (RE) elements and III-V semiconductors. One of the reasons is RE reacts with group-V elements to form lanthanoides such as ErP and ErAs. Incorporation of the lanthanoide layers in semiconductor heterostructures is expected to facilitate new physics in quantum-confined systems and novel electronic devices, since the lanthanoides exhibit semimetallic behavior.In this research project, we investigated atomicaily-controlled superKeterbepitaxy of ErP on InP substrates. Results obtained experimentally are summarized as follows :1 ) It has been found that there are appropriate Er sources for ErP growth. In the use of Er(DPM)_3, trisdipivaloymethanatoerbium, the deposit included no Er atoms, although the surface morphology changed drastically after the exposure to the Er source.2 ) ErP was grown on InP surfaces with various crystallographical orientations, (001), (011), (111)A and (111)B, which were controlled by selective-area growth technique. Large ErP islands with relatively flat top were successfully obtained on the (111)B surface.3 ) InP/ErP/InP doubleheterostructures were grown on (111)B InP substrates. Contrary to the structures on (001) substrates, InP cap layers were successfully grown in layer-by-layer mode on the ErP layer.4 ) At the initial stage for DyP/GaAs structures with good lattice-matching, Dy doping to III-V semiconductors were carried out. Well-controlled Dy doping was realized in GaAs and InP, using Dy(MeCp)_3, trismethylcyclopentadienyldysprosium. Characteristic Dy luminescence was observed, for the first time, in four wavelength regions in Dy-doped GaAs.