Photoluminescence of silicon nanowires obtained by epitaxial chemical vapor deposition

Olivier Demichel (1) , Fabrice Oehler (1) , Vincent Calvo (2, 3, 4, 1, 5) , Pierre Noé (6) , Nicolas Pauc (4) , Pascal Gentile (1, 7) , Pierre Ferret (8) , Thierry Baron (9, 10) , Noël Magnéa (11)

1 SiNaps - Silicon Nanoelectronics Photonics and Structures
2 GES - Groupe d'étude des semiconducteurs
3 INAC - Institut Nanosciences et Cryogénie
4 SP2M - UMR 9002 - Service de Physique des Matériaux et Microstructures
5 PHELIQS - PHotonique, ELectronique et Ingénierie QuantiqueS
6 LETI - Laboratoire d'électronique et des technologies de l'Information [Sfax]
7 PHELIQS - PHotonique, ELectronique et Ingénierie QuantiqueS
8 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
9 LTM - Laboratoire des technologies de la microélectronique
10 LTM - Laboratoire des technologies de la microélectronique
11 CEA GRENOBLE - Commissariat à l'Énergie Atomique (CEA) DRMFC

We have carried out photoluminescence measurements of silicon nanowires (SiNWs) obtained by the chemical vapor deposition method with a copper-catalyzed vapor–liquid–solid mechanism. The nanowires have a typical diameter of 200 nm. Spectrum of the as-grown SiNWs exhibits radiative states below the energy bandgap and a small contribution near the silicon gap energy at 1.08 eV. A thermal oxidation allows to decrease the intensity at low energy and to enhance the intensity of the 1.08 eV contribution. The behavior of this contribution as a function of the pump power is correlated to a free carrier recombination. Furthermore, the spatial confinement of the carriers in SiNWs could explain the difference of shape and recombination energy of this contribution compared to the recombination of free exciton in the bulk silicon. The electronic system seems to be in an electron–hole plasma (ehp), as it has already been shown in SOI structures [M. Tajima, et al., J. Appl. Phys. 84 (1998) 2224]. A simulation of the radiative emission of an ehp is performed and results are discussed.

Domains: Condensed Matter [cond-mat]; Materials Science [cond-mat.mtrl-sci]

Olivier Demichel, Fabrice Oehler, Vincent Calvo, Pierre Noé, Nicolas Pauc, et al.. Photoluminescence of silicon nanowires obtained by epitaxial chemical vapor deposition. Physica E: Low-dimensional Systems and Nanostructures, 2009, 41 (6), pp.963-965. ⟨10.1016/j.physe.2008.08.054⟩. ⟨hal-00455408⟩