New Quantum Optoelectronic Properties of Semiconductors with Disordered Structures

利用超高真空扫描隧道显微镜观察具有无序结构的半导体解理面，需要对解理面进行改造。经过与制造商的多次讨论，发明了不破坏表面观察功能的改造。本研究以InAs/GaAs量子点堆叠层为研究对象，探讨量子点有序或无序组装的形成条件。GaAs间隔层的厚度是变化的，因为间隔层的厚度影响点耦合的强度。通过高分辨电子显微镜的观察，我们得到以下结果：（1）当间隔层厚度在点高的1倍到2倍之间时，量子点相互耦合，有序组装;（2）当间隔层厚度小于点高时，量子点被破坏;（3）当间隔层厚度小于点高时，量子点不耦合，无序组装。 ...更多信息 比点的高度伊克尔。InAs/GaAs量子点的叠层结构提高了发光强度的饱和度，实验发现InGaN中存在相位分离。这种分离可用于GaN基质中InN的点形成。缩小尺寸是未来的主题。研究了等离子体激发对AlN层发光性能的影响，采用Stranski-Krastanov生长模式，在二维层的一定厚度（过渡厚度）处开始形成三维岛状结构，制备了量子点。在这项研究中推导出的解析方程，考虑到应变和表面能的岛屿和点。理论计算结果与实验结果吻合较好。无序超晶格的一些性质，如电子迁移率等，还没有得到精确的表征。当观察到低的电子迁移率时，它指示电子通过无序而定域。上海技术物理研究所已表示愿意为其进行表征，合作计划将继续下去。少

Remodeling has been requested to observe the cleaved surface of semiconductors with disordered structures by the ultra high vacuum scanning tunneling microscope. After several times of discussions with manufacturers, the remodeling which does not deteriorate the function of the surface observation was invented. It becomes possible to work continuously the research project.The stacked layrs of InAs/GaAs quantum dots were grown to investigate formation condigions for ordering or disordering assembling. The thickness of GaAs spacer is varied, since the spacer thickness affects to the strength of dot coupling. Through the observations of high resolution electron microscope, we obtain the following results : (1) quantum dots couple each other and assemble orderly if the spacer thickness is between single and twice much of the dot height, (2) they are destroyed if the spacer thickness is thinner than the dot height, (3) they do not couple and assemble disorderly if the spacer thickness is th … More icker than the dot height. The saturation in luminescence intensity is increased by the stacked layrs of InAs/GaAs quantum dots.The pahse separation in InGaN was experimentally discovered. This separation could be utilized for the dot formation of InN in GaN matrix. The size reduction is left as the future subject. The growth of the AIN layr is now investigated to see the effect of plasma exitation on the luminescence properties.Quantum dots have ben fabricated through the Stranski-Krastanov growth modein which three dimensional islands begin to be formed at the certain thickness of two dimensional layr : a transitional thickness. The analytical equation was derived in this study by taking the strain and the surface energy of the islands and the dots into account. The teoretical reults agree well with the experimental results. The equation can be applied to other heteroepitaxial systems.There are some properties of disordered superlattices which have not been characterized yet such as electron mobility. When the low electron mobility is observed, it indicates the localizations of electrons by disordering. Shanghai Institute of Technical Physics has offered to characterize it. The collaboration scheme will be continued. Less