Polarity analysis of GaN nanorods by photo-assisted Kelvin probe force microscopy
| Autor: | Stephan Merzsch, M. Al-Suleiman, Ü. Sökmen, Shunfeng Li, Sönke Fündling, Jiandong Wei, Hergo-H. Wehmann, Richard Neumann, Andreas Waag, Xue Wang |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
010302 applied physics
Kelvin probe force microscope Materials science business.industry Surface photovoltage Analytical chemistry 02 engineering and technology Substrate (electronics) 021001 nanoscience & nanotechnology Condensed Matter Physics Epitaxy 01 natural sciences 0103 physical sciences Microscopy Sapphire Optoelectronics Nanorod Metalorganic vapour phase epitaxy 0210 nano-technology business |
| Zdroj: | physica status solidi (c) |
| ISSN: | 1862-6351 |
| DOI: | 10.1002/pssc.201000982 |
| Popis: | Polarity dependence (N-polar (000-1) and Ga-polar (0001)) of surface photovoltage of epitaxially grown, vertically aligned GaN nanorods has been investigated by photo-assisted Kelvin probe force microscopy (KPFM). Commercial GaN substrates with known polarities are taken as reference samples. The polarity of GaN substrates can be well distinguished by the change in surface photovoltage upon UV illumination in air ambient. These different behaviors of Ga- and N-polar surfaces are attributed to the polarity-related surface-bound charges and photochemical reactivity. GaN nanorods were grown on patterned SiO2/sapphire templates by metal-organic vapor phase epitaxy (MOVPE). In order to analyze the bottom surface of the grown GaN nanorods, a technique known from high power electronics and joining techniques is applied to remove the substrate. The top and bottom surfaces of the GaN nanorods are identified to be N-polar and Ga-polar according to the KPFM results, respectively. Our experiments demonstrate that KPFM is a simple and suitable method capable to identify the polarity of GaN nanorods. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) |
| Databáze: | OpenAIRE |
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