Abstract
We report the controlled growth of vertically aligned GaAs/AlGaAs core-shell nanowires. By optimizing the shell deposition temperature and catalyst density we maintain high temperature stability and achieve defect-free epitaxial AlGaAs shell deposition with high aluminum incorporation. Energy dispersive x-ray analysis determines the shell composition to be Al0.9 Ga0.1 As and measures the uniformity of the shell thickness. Lattice-resolved high-angle annular dark-field scanning transmission electron microscopy images confirm the core-shell interface to be defect-free, epitaxial, and atomically sharp. The ability to realize GaAs/AlGaAs core-shell nanowires with precise control over the morphology and composition is essential to the development of nanowire-based high mobility electronics.
| Original language | English |
|---|---|
| Article number | 151917 |
| Journal | Applied Physics Letters |
| Volume | 93 |
| Issue number | 15 |
| DOIs | |
| State | Published - 2008 |
| Externally published | Yes |
Funding
The authors thank E. A. Fitzgerald for access to MOCVD facilities, the MIT Center for Materials Science and Engineering, a NSF-funded MRSEC, for use of electron microscopy facilities, and S. T. Boles for MOCVD assistance and helpful discussions. S.K.L. acknowledges the Cambridge Foundation for graduate research fellowship support. S.G. acknowledges 3M, the Interconnect Focus Center, and MIT startup funds for financial support. A portion of this research was conducted at the SHaRE User Facility, which is sponsored by the Division of Scientific User Facilities, Office of Basic Energy Sciences, U.S. Department of Energy.
| Funders | Funder number |
|---|---|
| Cambridge Foundation | |
| Division of Scientific User Facilities | |
| Interconnect Focus Center | |
| Office of Basic Energy Sciences | |
| U.S. Department of Energy | |
| 3M | |
| Massachusetts Institute of Technology |