title: Direct-bandgap luminescence at room-temperature from highly-strained Germanium nanocrystals.
abstract: Efficient room-temperature luminescence at optical telecommunication wavelengths and originating from direct band-to-band recombination has been observed in tensile-strained germanium nanocrystals synthesized by mechanical grinding techniques. Selected area electron diffraction, micro-Raman and optical-absorption spectroscopy measurements indicate high tensile-strains while combined photoluminescence spectroscopy, excitation-power evolution and time-resolved measurements suggest direct band-to-band recombination. Such band-engineered germanium nanocrystals offer great possibilities for silicon-photonics integration due to their superb light-emission properties, facile fabrication and compatibility with standard microelectronic processes.
authors.affiliation: Department of Electrical & Computer Engineering, University of Delaware, 140 Evans Hall, Newark, DE 19716, USA.
authors.forename: Latha
authors.initials: L
authors.lastname: Nataraj
authors.forename: Fan
authors.initials: F
authors.lastname: Xu
authors.forename: Sylvain G
authors.initials: SG
authors.lastname: Cloutier
mesh_terms: D005857:Germanium / Q000737:chemistry; D008027:Light; D049449:Luminescence; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods*; D055095:Optics and Photonics; D012666:Semiconductors; D013053:Spectrophotometry / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013696:Temperature; D013718:Tensile Strength
chemical_list: D005857:Germanium