The role of quantum-confined excitons vs defects in the visible luminescence of SiO{sub 2} films containing Ge nanocrystals

Journal Article · Mon Apr 01 04:00:00 EST 1996 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.115838· OSTI ID:283782

Min, K S; Shcheglov, K V; Yang, C M; Atwater, H A ^[1]; Brongersma, M L; Polman, A ^[2]

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1. Thomas J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California 91125 (United States)
2. FOM Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam (The Netherlands)

Synthesis of Ge nanocrystals in SiO{sub 2} films is carried out by precipitation from a supersaturated solid solution of Ge in SiO{sub 2} made by Ge ion implantation. The films exhibit strong room-temperature visible photoluminescence. The measured photoluminescence peak energy and lifetimes show poor correlations with nanocrystal size compared to calculations involving radiative recombination of quantum-confined excitons in Ge quantum dots. In addition, the photoluminescence spectra and lifetime measurements show only a weak temperature dependence. These observations strongly suggest that the observed visible luminescence in our samples is not due to the radiative recombination of quantum-confined excitons in Ge nanocrystals. Instead, observations of similar luminescence in Xe{sup +}-implanted samples and reversible PL quenching by hydrogen or deuterium suggest that radiative defect centers in the SiO{sub 2} matrix are responsible for the observed luminescence. {copyright} {ital 1996 American Institute of Physics.}

• OSTI ID: 283782
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 18 Vol. 68; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARRIER LIFETIME
COMPOSITE MATERIALS
CONFINEMENT
CRYSTAL DEFECTS
EXCITONS
ION IMPLANTATION
PHOTOLUMINESCENCE
RECOMBINATION
SILICON
SILICON OXIDES