title: Size-controlled Ge nanostructures for enhanced Er³⁺ light emission.
abstract: The potential of Ge nanoparticles (NPs) embedded in Al2O3 with tunable effective optical bandgap values in the range of 1.0-3.3 eV to induce enhanced Er3+ light emission is investigated. We demonstrate nonresonant indirect excitation of the Er3+ ions mediated by the Ge NPs at room temperature. Efficient Er3+ light emission enhancement is obtained for Ge NPs with large effective optical bandgaps in the range of 1.85 to 2.8 eV. The coupled Ge NP-Er emission shows a negligible thermal quenching from 10 K to room temperature that is related to Er3+ de-excitation through thermally activated defect states.
authors.forename: Javier
authors.initials: J
authors.lastname: Martín-Sánchez
authors.forename: Rosalía
authors.initials: R
authors.lastname: Serna
authors.forename: J
authors.initials: J
authors.lastname: Toudert
authors.forename: Benito
authors.initials: B
authors.lastname: Alén
authors.forename: Carmen
authors.initials: C
authors.lastname: Ballesteros