Efficient methodology to correlate structural with optical properties of GaAs nanowires based on scanning electron microscopy
| Autor: | Wan-Hsien Lin, Esperanza Luna, Oliver Brandt, Hanno Küpers, Uwe Jahn, Ryan B. Lewis, Lutz Geelhaar |
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| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science business.industry Scanning electron microscope Mechanical Engineering Resolution (electron density) Nanowire Analytical chemistry Bioengineering Cathodoluminescence 02 engineering and technology General Chemistry 021001 nanoscience & nanotechnology 01 natural sciences Mechanics of Materials 0103 physical sciences Microscopy Optoelectronics General Materials Science Electrical and Electronic Engineering 0210 nano-technology business Crystal twinning Wurtzite crystal structure Electron backscatter diffraction |
| Zdroj: | Nanotechnology. 28(41) |
| ISSN: | 1361-6528 |
| Popis: | Twin boundaries and boundaries between zincblende (ZB) and wurtzite (WZ) segments of GaAs-related nanowires (NWs) form intrinsic heterointerfaces with essential consequences for the application of such nanomaterials in optoelectronic devices. We show that for GaAs and GaAs/(Al, Ga)As core/shell NWs, crystal twinning along the NW axis can be imaged with a spatial resolution of 10 nm using secondary electrons in a scanning electron microscope (SEM). Changes of the crystal structure from the ZB to the WZ phase have been investigated by electron backscatter diffraction. In addition to these methods, we employ spectrally and spatially resolved cathodoluminescence measurements in the same SEM to study the correlation between the structural and optical properties in single NWs. Two GaAs/AlAs/GaAs core/shell/shell NWs differing significantly in the crystal structure along their axis have been investigated combining these three techniques in order to demonstrate the strength of the employed methodology. Our experiments show that based on commonly available SEM methods, an overview of the structural properties along an entire NW and their impact on the spectral and spatial luminescence distribution can be efficiently obtained providing a quick feedback for the optimization of growth conditions. |
| Databáze: | OpenAIRE |
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