Tailoring Optical Properties of Semiconductor Nanomaterials
Silvija Gradečak, Assistant Professor, Department of Materials Science and Engineering
This project will concentrate on direct correlation of structural/optical properties with high spatial resolution, where semiconductor nanowires will serve as a model system. Ultimately, it seeks to answer the following questions: (1) what are the critical structure-property relationships in semiconductor nanowires and nanowire heterostructures that govern electrical and optical properties on the nanoscale? (2) How can this knowledge be used to predict and tailor properties of semiconductor nanowires (materials-on-demand) for specific applications in nanophotonics and nanoelectronics?
The approach combines novel nanowire growth techniques and in-situ electron microscopy characterization techniques for direct correlation of structural and physical properties on the nanoscale. Cathodoluminescence (CL) in scanning transmission electron microscopy (STEM) is one of the techniques that will be of particular importance for this study. CL-STEM has recently been installed in the CMSE electron microscopy center (as the only instrument of its kind in the U.S.). It is anticipated that this seed research will significantly contribute to fundamental understanding of optical properties of 1D systems through a combination of rational nanowire synthesis, comprehensive structural and optical characterization, and electrical measurements.
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Figure: Schematic drawing of the collection of CL in the TEM-CL that consists of the TEM, monochromator, and photodetectors. |
