二六族半導體奈米結構之磁光研究

Abstract

雖然量子態的絕對相位是不可測量的，但是同調帶電物質波是可被測量的。近年來，磁通量在激子活化能上的效應引起很大的注意。在此論文中，在高達十四特斯拉磁場裡，我們將會呈現在三種不同的二六族半導體奈米結構系統所做的磁光研究的光學性質。在type-II CdTe/CdS/ZnS 奈米粒子系統中，在螢光光譜上的峰值能量及發光強度隨著磁場變化振盪的情形被觀察到，且歸因於類似Aharonov-Bohm 效應。在type-II ZnTe/ZnSe 量子點系統中，我們同時地從不同大小的量子點中觀察到不同的AB週期在同一個系統中，且觀察到雜質或缺陷破壞AB振盪的轉動對襯造成的影響。在Zn-Se-Te 多層系統中，我們同時地在同一個樣品裡從不同的螢光波峰觀察到不同AB振盪行為。

Although the absolute phase of a quantum state is not measurable, the relative phase of a coherent charged particle wave could be manipulated. Recently, the effect of the magnetic flux on the excitonic energy has received much attention. In this thesis, we’ll present our magneto-photoluminescence studies on the optical properties of three different II-VI semiconductor nanostructurte systems in magnetic field up to 14 T. In type-II CdTe/CdSe/ZnS nanoparticle system, oscillation on the peak energy of the photoluminescence spectra as well as oscillation in the integrated intensity as a function of magnetic field were observed and are attributed to the optical Aharonov-Bohm-like effect. In type-II ZnTe/ZnSe QDs system, we observed different AB periods from different sizes of quantum dots simultaneously in the same system and also observed the influence caused by impurities or defects breaking the rotational symmetry of AB oscillation. In Zn-Se-Te multilayer system, we observed different AB oscillatory behavior from different PL emission peak of the same sample simultaneously.