| Autor: |
Beznasyuk, Daria V., Robin, Eric, Hertog, Martien Den, Claudon, Julien, Hocevar, Moïra |
| Rok vydání: |
2017 |
| Předmět: |
|
| Zdroj: |
Nanotechnology 2017 |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1088/1361-6528/aa7d40 |
| Popis: |
We report on the growth of axial InAs-on-GaAs nanowire heterostructures on silicon by molecular beam epitaxy using 20 nm diameter Au catalysts. First, the growth parameters of the GaAs nanowire segment were optimized to achieve a pure wurtzite crystal structure. Then, we developed a two-step growth procedure to enhance the yield of vertical InAs-on-GaAs nanowires. We achieved 90% of straight InAs-on-GaAs nanowires by further optimizing the growth parameters. We investigated the composition change at the interface by energy dispersive X-ray spectroscopy and the nanowire crystal structure by transmission electron microscopy. The nominal composition of the InAs segment is found to be In$_{x}$Ga$_{1-x}$As with $x$=0.85 and corresponds to 6% of lattice mismatch with GaAs. Strain mapping performed by the geometrical phase analysis of high-resolution images revealed a dislocation-free GaAs/InAs interface. In conclusion, we successfully fabricated highly mismatched heterostructures, confirming the prediction that axial GaAs/InAs interfaces are pseudomorphic in nanowires below 40 nm diameter. |
| Databáze: |
arXiv |
| Externí odkaz: |
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