Microscopic Correlation of Electronic and Optical Properties with the Crystalline Real Structure of Polarization Field Controlled Group-III-Nitrides

为了详细了解复杂的半导体异质结构和基于它们的器件的物理特性，必须在微米或纳米尺度上系统地确定和关联结构，化学，电子和光学特性。发光技术是半导体研究中最灵敏、最无损的方法之一，阴极发光显微镜技术将时间分辨发光光谱与扫描电子显微镜的高空间分辨率相结合，为半导体及其异质结构和界面的光学纳米表征提供了强有力的工具。作为研究小组提案“氮化物光发射器中的偏振场控制”的一部分，我们将在微米和纳米尺度上将非极性和半极性外延氮化物结构的电子和光学特性与晶体真实的结构相关联。我们希望直接在（扫描）透射电子显微镜中使用阴极发光显微镜的最高空间分辨率，以获得堆垛层错和位错对发光的影响。纳米局域化和极化场对三元和四元合金复合动力学的作用将通过我们的“标准”SEM CL以及我们的TEM-CL进行分析。高铟含量的纳米结构将被全面研究。将进行真实的结构和复合动力学的微观关联。空间-时间分辨的ps-阴极发光光谱成像能够确定结构缺陷和内部场对复合动力学的影响，并在半极性和非极性InGaN量子阱中产生过量的横向输运。

For a detailed understanding of complex semiconductor heterostructures and the physics of devices based on them, a systematic determination and correlation of the structural, chemical, electronic, and optical properties on a micro- or nano-scale is mandatory. Luminescence techniques belong to the most sensitive, non-destructive methods of semiconductor research, and the combination of time-resolved luminescence spectroscopy with the high spatial resolution of a scanning electron microscope, as realized by the technique of cathodoluminescence microscopy, provides a powerful tool for the optical nano-characterization of semiconductors, their heterostructures as well as their interfaces. As part of the research group proposal “Polarization field control in nitride light emitters” we shall correlate the electronic and optical properties of non- and semipolar epitaxial nitride structures on a micro- and nano-scale with the crystalline real structure.- We want to use highest spatial resolution by cathodoluminescence microscopy directly in a (scanning) transmission electron microscope to obtain the impact of stacking faults and dislocations on luminescence.- The role of nano-localization and polarization fields on recombination kinetics in ternary and quaternary alloys will be analyzed by our “standard” SEM-based CL as well as our TEM-CL.- High indium content nanostructures will be comprehensively studied.- A microscopic correlation of real structure and recombination kinetics will be performed. The spatio-time-resolved ps-cathodoluminescence spectroscopy imaging is able to determine the influence of structural defects and internal fields on the recombination dynamics and gives excess to the lateral transport in semi- and non-polar InGaN QWs.