Verallgemeinerte Ferninfrarot-Ellipsometrie von Ladungsträger-Magnetfeld-Effekten in III-V Verbindungshalbleiter Schichtstrukturen

用磁光椭偏法精确测定了多合金锌闪锌矿iii族- v族半导体的电子和空穴有效质量m*、迁移率u及其与载流子浓度N的依赖关系。本提案中研究的技术重要性和当前科学兴趣的材料分别是AIGaInP和硼或氮稀释的InGaAs合金。通过金属-有机气相外延，可以在n、u值足够高的情况下生长出n型或p型晶体，并具有优异的晶体质量。当进入磁场时，自由载流子在远红外波长处引起双折射，从而相互独立地访问N， m*和u。目前完全缺乏测量半导体层结构中复值磁光双折射的工具。我们将(1)建立一个新的远红外磁光椭偏仪，该椭偏仪能达到B =±6 Tesla, T = 4K。(2)利用远红外磁光广义椭偏法测定半导体层结构中n型或p型材料的自由载流子诱导磁光双折射，作为磁场强度和样品温度的函数。(3)以n型和p型AIGalnP、InGaNAs和BInGaAs合金为例，测定m、p、n，并随后评估I′点附近可达价带和导带的色散。阐明光学载流子散射机理。

The electron and hole effective mass m* and mobility u, and their dependence an the carrier concentration N shall be accurately determined using magnetooptic ellipsometry for exemplary multinary alloy zincblende group-III-group-V semiconductors. Materials of technological importance and current scientific interest investigated in this proposal are AIGaInP, and boron or nitrogen diluted InGaAs alloys, respectively. They can be grown n- or p-type with sufficiently high values of N, and u, and with excellent crystal quality by metal-organic vaporphase-epitaxy. When brought into magnetic fields, the free carriers cause birefringence at far-infrared wavelengths providing access to N, m*, and ,u independently from each other. Tools for the determination of the complex-valued magnetooptic birefringence in semiconductor layer structures are lacking completely at present. We will (1) setup a new far-infrared magnetooptic ellipsometer capable of reaching B = ±6 Tesla, and T = 4K ... 293K at the sample, and (2) determine the free-carrier-induced magnetooptic birefringence of n- or p-type materials within semiconductor layer structures, as a function of the magnetic field strength and Sample temperature, by far-infrared magnetooptic generalized ellipsometry, and (3) determine m, p, N, exemplarily for n- and p-type AIGalnP, InGaNAs, and BInGaAs alloys, and subsequently evaluate the dispersion of the accessible valence and conduction bands in the vicinity of the I'-point, and elucidate optical carrier scattering mechanisms.