Visible and infrared photoluminescence from erbium-doped silicon nanocrystals p...

• Author(s): Cerqueira, M. F. ; Losurdo, M. ; Monteiro, T. ; Stepikhova, M. ; Soares, Manuel Jorge ; Peres, M. ; Alpuim, P.
• Date: 2007
• Persistent ID: http://hdl.handle.net/1822/13772
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): Erbium-doped; Low-dimensional Si films; Optical properties; Spectroscopic ellipsometry
• Document Type: Article
• Language: English

Description

Erbium-doped low-dimensional Si films with different microstructures were deposited by reactive magnetron sputtering on glass substrates by varying the hydrogen flow rate during deposition. Amorphous, micro- and nanocrystalline samples, consisting of Si nanocrystalls embedded in silicon-based matrices with different structures, were achieved with optical properties in the visible and IR depending on nanocrystalline fraction and matrix structure and chemical composition. Structural characterization was performed by X-ray diffraction in the grazing incidence geometry and Raman spectroscopy. The chemical composition was studied using RBS/ERD techniques. Spectroscopic ellipsometry was combined with the previous techniques to further re-solve the film microstructure and composition. In particular, the distribution along the film thickness of the volume fractions of nanocrystalline/amorphous silicon and SiOx phases has been obtained. In this contribution we discuss visible and infrared photoluminescence as a function of sample microstructure and of the oxygen/ hydrogen concentration ratio present in the matrix.