Tunneling and optical spectroscopy performed on InAs nanorods 7-25 nm long, reveal a clear dependence of the band gap on length. This (zero-dimension like) behavior is different from that of CdSe rods, where the band gap is nearly independent of length, a signature of quasi-one-dimensionality. The transition between these two regimes is governed by the ratio between the Bohr radius and the nanorods length. The gaps measured by tunneling spectroscopy are larger than the optical gaps by a factor that depends on the tunneling configuration. This is attributed to a combination of the Coulomb interaction and the voltage division between the two tunnel junctions in the STM experiment. However, the tunneling gaps were found to reduce in dense aggregates of rods.
|Number of pages
|Physica E: Low-Dimensional Systems and Nanostructures
|Published - Feb 2005
|International Conference on Quantum Dots - Banff, Alberta, Canada
Duration: 10 May 2004 → 13 May 2004
Bibliographical noteFunding Information:
We thank Dr. Inna Popov and Avi Ben-Chur, from the Unit for Nanocharacterization of the Hebrew University Center for Nanoscience and Nanotechnology for the electron microscopy characterization of the nanorods samples. This work was supported in part by grants from the Israel-US Binational Foundation, the Germin-Israel Program (DIP), and the Israel Science Foundation.
- Quantum confinement
- Scanning tunneling spectroscopy
- Single electron tunneling