title: Photoluminescence efficiency and size distribution of self assembled ge dots on porous TiO2.
abstract: For Ge nanodots approximately 20 nm in diameter grown by annealing a thin amorphous Ge layer deposited by molecular beam epitaxy on a mesoporous TiO2 layer on Si(001), photoluminescence (PL) was observed as a wide near-infrared band near 800 meV. Using a tight binding theoretical model, the energy-dependent PL spectrum was transformed into a dependence on dot size. The average dot size determined the peak energy of the PL band and its shape depended on the size distribution, including bandgap enlargement due to quantum confinement. Combining the dot sample PL with an established dependence of emission efficiency on dot diameter, it was possible to derive a dot size distribution and compare it with results obtained independently from atomic force microscopy.
authors.affiliation: National Research Council of Canada, 1200 Montreal Road, Ottawa, ON K1A OR6, Canada. 2lM2NP CNRS-UniversityAix Marseille, Campus St. Jdrdme, Case 142, 13397 Marseille CEDEX 20, France 3Laboratoire Chimie de la Matidre Condensde de Paris, UMR-7574 UPMC-CNRS, College de France, 11, place Marcelin Berthelot, 75231 Paris, France.
authors.forename: Nelson L
authors.initials: NL
authors.lastname: Rowell
authors.forename: David J
authors.initials: DJ
authors.lastname: Lockwood
authors.forename: Guillaume
authors.initials: G
authors.lastname: Amiard
authors.forename: Luc
authors.initials: L
authors.lastname: Favre
authors.forename: Antoine
authors.initials: A
authors.lastname: Ronda
authors.forename: Isabelle
authors.initials: I
authors.lastname: Berbezier
authors.forename: Marco
authors.initials: M
authors.lastname: Faustini
authors.forename: David
authors.initials: D
authors.lastname: Grosso