Optical and Far Infrared Studies of Semiconductor Heterostructures

9705064 Dobrowolska这是一个研究半导体异质结构的更新方案。分子束外延(MBE)将用于制备三种新的半导体系统：II-VI自组装量子点、稀磁III-V半导体和II-VI半导体微腔。自组装量子点项目将重点研究生长在ZnSe上的CdSe量子点。将通过分子束外延生长III-V化合物和锰硫化物(例如，MnTe)的固溶体来尝试形成III-V磁性系统。最后，II-VI型微腔的制作将集中在用于锌硒/锌镉硒量子井结构的分布布拉格反射器的分子束外延制备。上述体系将通过光致发光光谱、光吸收和磁光方法进行研究。所有这三个项目都涉及与半导体异质结构的光电应用相关的基本问题。%这是研究半导体异质结的更新方案。由不同半导体(“异质结构”)交替层组成的薄膜系统在发光二极管、半导体激光器和传感器等重要技术设备中发挥着关键作用。分子束外延是一种形成这种原子级完美的多层膜的方法。本项目将把这一方法应用于三个新的前沿领域：在所有三个方向上形成100个原子的半导体结构(“量子点”)；形成具有重要技术意义的磁性半导体，其性质可因磁场而改变；以及制造对蓝光发射器的运作具有直接重要性的“微腔”。对这些系统的光学研究有望为新的光电子应用铺平道路。***

9705064 Dobrowolska This is a renewal proposal to study semiconductor heterostructures. Molecular beam epitaxy (MBE) will be used to fabricate three new semiconductor systems: II-VI self-assembled quantum dots (QDs); diluted magnetic III-V semiconductors; and II- VI semiconductor microcavities. The self-assembled QD project will focus on investigation of CdSe QDs grown on ZnSe. Formation of III-V magnetic systems will be attempted by MBE growth of solid solutions of III-V compounds and Mn chalcogenides (e.g., MnTe). Finally, fabrication of II-VI microcavities will focus on MBE fabrication of distributed Bragg reflectors for ZnSe/ZnCdSe quantum well structures. The above systems will be investigated by photoluminescence spectroscopy, optical absorption, and magneto-optical methods. All three projects address fundamental issues relevant to optoelectronic applications of semiconductor heterostructures. %%% This is a renewal proposal to study semiconductor heterostructures. Thin film systems consisting of alternating layers of dissimilar semiconductors ("heterostructures") play a critical role in technologically important devices, such as light emitting diodes, semiconductor lasers, and sensors. Molecular beam epitaxy is a method of forming such multilayers with unprecedented atomic-scale perfection. The present project will apply this method to three new frontiers: the formation of semiconductor structures on the scale of 100 atoms in all three directions ("quantum dots"); the formation of technologically important magnetic semiconductors whose properties can be varied by magnetic field; and fabrication of "microcavities" of immediate importance to the operation of blue light emitters. Optical studies of these systems are expected to pave the way toward new optoelectronic applications. ***