title: Large and Uniform Optical Emission Shifts in Quantum Dots Strained along Their Growth Axis.
abstract: We introduce a calibration method to quantify the impact of external mechanical stress on the emission wavelength of distinct quantum dots (QDs). Specifically, these emitters are integrated in a cross-section of a semiconductor core wire and experience a longitudinal strain that is induced by an amorphous capping shell. Detailed numerical simulations show that, thanks to the shell mechanical isotropy, the strain in the core is uniform, which enables a direct comparison of the QD responses. Moreover, the core strain is determined in situ by an optical measurement, yielding reliable values for the QD emission tuning slope. This calibration technique is applied to self-assembled InAs QDs submitted to incremental elongation along their growth axis. In contrast to recent studies conducted on similar QDs submitted to a uniaxial stress perpendicular to the growth direction, optical spectroscopy reveals up to ten times larger tuning slopes, with a moderate dispersion. These results highlight the importance of the stress direction to optimize the QD optical shift, with general implications, both in static and dynamic regimes. As such, they are in particular relevant for the development of wavelength-tunable single-photon sources or hybrid QD opto-mechanical systems.
authors.affiliation: Univ. Grenoble Alpes , F-38000 Grenoble, France.|CEA, INAC-PHELIQS , "Nanophysique et semiconducteurs" group, F-38000 Grenoble, France.
authors.forename: Petr
authors.initials: P
authors.lastname: Stepanov
authors.affiliation: Univ. Grenoble Alpes , F-38000 Grenoble, France.|CEA, INAC-MEM , F-38000 Grenoble, France.|ESRF-The European Synchrotron , 38043 Grenoble Cedex 9, France.
authors.forename: Marta
authors.initials: M
authors.lastname: Elzo-Aizarna
authors.affiliation: Univ. Grenoble Alpes , F-38000 Grenoble, France.|CEA, INAC-PHELIQS , "Nanophysique et semiconducteurs" group, F-38000 Grenoble, France.
authors.forename: Joël
authors.initials: J
authors.lastname: Bleuse
authors.affiliation: Univ. Grenoble Alpes , F-38000 Grenoble, France.|CEA, INAC-PHELIQS , "Nanophysique et semiconducteurs" group, F-38000 Grenoble, France.
authors.forename: Nitin S
authors.initials: NS
authors.lastname: Malik
authors.affiliation: Univ. Grenoble Alpes , F-38000 Grenoble, France.|CEA, INAC-PHELIQS , "Nanophysique et semiconducteurs" group, F-38000 Grenoble, France.
authors.forename: Yoann
authors.initials: Y
authors.lastname: Curé
authors.affiliation: Univ. Grenoble Alpes , F-38000 Grenoble, France.|CEA, CNRS, INAC-SPINTEC , F-38000 Grenoble, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Gautier
authors.affiliation: Univ. Grenoble Alpes , F-38000 Grenoble, France.|CEA, INAC-MEM , F-38000 Grenoble, France.|Institut Universitaire de France , 75231 Paris, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Favre-Nicolin
authors.affiliation: Univ. Grenoble Alpes , F-38000 Grenoble, France.|CEA, INAC-PHELIQS , "Nanophysique et semiconducteurs" group, F-38000 Grenoble, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Gérard
authors.affiliation: Univ. Grenoble Alpes , F-38000 Grenoble, France.|CEA, INAC-PHELIQS , "Nanophysique et semiconducteurs" group, F-38000 Grenoble, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Claudon
keywords: Quantum dot; core−shell nanowire; elastic tuning; hybrid opto-mechanics; photoluminescence; quantum optics