| Full text | |
| Author(s): |
Moller, M.
;
Oliveira, D. S.
;
Sahoo, P. K.
;
Cotta, M. A.
;
Iikawa, F.
;
Motisuke, P.
;
Molina-Sanchez, A.
;
de Lima, Jr., M. M.
;
Garcia-Cristobal, A.
;
Cantarero, A.
Total Authors: 10
|
| Document type: | Journal article |
| Source: | Nanotechnology; v. 28, n. 29 JUL 21 2017. |
| Web of Science Citations: | 1 |
| Abstract | |
InAs nanowires grown by vapor-liquid-solid (VLS) method are investigated by photoluminescence. We observe that the Fermi energy of all samples is reduced by similar to 20 meV when the size of the Au nanoparticle used for catalysis is increased from 5 to 20 nm. Additional capping with a thin InP shell enhances the optical emission and does not affect the Fermi energy. The unexpected behavior of the Fermi energy is attributed to the differences in the residual donor (likely carbon) incorporation in the axial (low) and lateral (high incorporation) growth in the VLS and vapor-solid (VS) methods, respectively. The different impurity incorporation rate in these two regions leads to a core/shell InAs homostructure. In this case, the minority carriers (holes) diffuse to the core due to the built-in electric field created by the radial impurity distribution. As a result, the optical emission is dominated by the core region rather than by the more heavily doped InAs shell. Thus, the photoluminescence spectra and the Fermi energy become sensitive to the core diameter. These results are corroborated by a theoretical model using a self-consistent method to calculate the radial carrier distribution and Fermi energy for distinct diameters of Au nanoparticles. (AU) | |
| FAPESP's process: | 15/16611-4 - III-V semiconductor nanowires: synthesis studies for biology applications |
| Grantee: | Mônica Alonso Cotta |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 12/22617-7 - Optical properties of InAs nanowires |
| Grantee: | Fernando Iikawa |
| Support Opportunities: | Research Grants - Visiting Researcher Grant - International |
| FAPESP's process: | 16/16365-6 - Nanostructures of III-V semiconductors and their optical properties |
| Grantee: | Fernando Iikawa |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 13/02300-1 - Semiconductor nanowires: formation mechanisms and biosensing applications |
| Grantee: | Mônica Alonso Cotta |
| Support Opportunities: | Regular Research Grants |