Germanium doping of self-assembled GaN nanowires grown by plasma-assisted molecular beam epitaxy
Abstract
Germanium doping of GaN nanowires grown by plasma-assisted molecular beam epitaxy on Si(111) substrates is studied. Time of flight secondary ion mass spectrometry measurements reveal a constant Ge-concentration along the growth axis. A linear relationship between the applied Ge-flux and the resulting ensemble Ge-concentration with a maximum content of 3.3×1020 cm-3 is extracted from energy dispersive X-ray spectroscopy measurements and confirmed by a systematic increase of the conductivity with Ge-concentration in single nanowire measurements. Photoluminescence analysis of nanowire ensembles and single nanowires reveals an exciton localization energy of 9.5 meV at the neutral Ge-donor. A Ge-related emission band at energies above 3.475 eV is found that is assigned to a Burstein-Moss shift of the excitonic emission.
- Publication:
-
Journal of Applied Physics
- Pub Date:
- September 2013
- DOI:
- 10.1063/1.4820264
- Bibcode:
- 2013JAP...114j3505S
- Keywords:
-
- electrical conductivity;
- elemental semiconductors;
- excitons;
- gallium compounds;
- germanium;
- III-V semiconductors;
- molecular beam epitaxial growth;
- nanofabrication;
- nanowires;
- photoluminescence;
- plasma materials processing;
- secondary ion mass spectra;
- self-assembly;
- semiconductor doping;
- semiconductor epitaxial layers;
- semiconductor growth;
- time of flight mass spectra;
- wide band gap semiconductors;
- X-ray chemical analysis;
- 81.16.Dn;
- 68.55.ag;
- 73.61.Ey;
- 78.55.Cr;
- 78.66.Fd;
- 81.15.Hi;
- Self-assembly;
- Semiconductors;
- III-V semiconductors;
- III-V semiconductors;
- III-V semiconductors;
- Molecular atomic ion and chemical beam epitaxy