High-field studies of the band dispersion in novel semiconductor materials: Dilute nitride semiconductors and Ge/SiGe quantum wells

点击翻译按钮获取中文摘要

In the first part, the project aims to systematically study the effect of nitrogen concentration on the effective mass of InAs1-xNx, GaAs1-xNx, and InSb1-xNx, which is of key importance for understanding the fundamentals of the conduction bandstructure modification due to the incorporation of nitrogen. The most direct experiment, high field cyclotron resonance (CR) absorption, will be performed on sets of samples with various nitrogen content under wide range of excitation wavelengths and temperatures. The CR measurements will be completed with other common indirect methods, including infrared 3 reflectivity and magneto-photoluminescence studies in order to understand the origin of the highly dispersed values of the effective mass published in the literature.In the second part, the attention is addressed to Ge/SiGe heterostructures, which are promising candidates to replace Si/SiGe systems in the next generation of high speed electronics, due to higher intrinsic carrier mobility in Germanium. The effect of biaxial strain on the hole effective mass and the valence band energy dispersion will be studied using high field CR under wide range of excitation wavelength.