Publications de Sebastian Pascal Tamariz Kaufmann

Single photon emission and recombination dynamics in self-assembled GaN/AlN quantum dots

Nicolas Grandjean, Raphaël Butté, Sebastian Pascal Tamariz Kaufmann, Johann Nicolaï Stachurski, Gordon Jens Callsen

Y III-nitride quantum dots (QDs) are a promising system actively studied for their ability to maintain single photon emission up to room temperature. Here, we report on the evolution of the emission properties of self-assembled GaN/ AlN QDs for temperature ...

SPRINGERNATURE2022

Dark-level trapping, lateral confinement, and built-in electric field contributions to the carrier dynamics in c-plane GaN/AlN quantum dots emitting in the UV range

Nicolas Grandjean, Raphaël Butté, Sebastian Pascal Tamariz Kaufmann

c-plane GaN/AlN quantum dots (QDs) are promising zero-dimensional quantum nanostructures that exhibit single photon emission properties up to room temperature and even above. In this context, it is of prime interest to gain a deeper insight into the recomb ...

AMER INST PHYSICS2021

Toward Bright and Pure Single Photon Emitters at 300 K Based on GaN Quantum Dots on Silicon

Nicolas Grandjean, Raphaël Butté, Sebastian Pascal Tamariz Kaufmann, Johann Nicolaï Stachurski, Kanako Shojiki, Gordon Jens Callsen

Quantum dots (QDs) based on III-nitride semi-conductors are promising for single photon emission at noncryogenic temperatures due to their large exciton binding energies. Here, we demonstrate GaN QD single photon emitters operating at 300 K with g((2)) (0) ...

AMER CHEMICAL SOC2020

GaN Quantum Dots for Room Temperature Excitonic Physics

Sebastian Pascal Tamariz Kaufmann

Quantum dots (QDs) are the result of quantum confinement in the three spatial directions, as such they exhibit remarkable properties, of which the most important is perhaps the absence of a continuum of states. The allowed energetic levels are discrete, si ...

EPFL2019

Density control of GaN quantum dots on AlN single crystal

Nicolas Grandjean, Sebastian Pascal Tamariz Kaufmann, Gordon Jens Callsen

Full control over the density and emission properties of GaN quantum dots (QDs) should be feasible, provided that the growth proceeds in the Stranski-Krastanov (SK) growth mode. In this work, we derive the phase diagram for GaN QD formation on AlN by NH3-m ...

2019

Room temperature single photon emission from planar GaN/AlN quantum dot samples grown by MBE

Nicolas Grandjean, Sebastian Pascal Tamariz Kaufmann, Gordon Jens Callsen

We present an overview on the growth and the optical properties of GaN quantum dots (QDs) embedded in planar AlN grown on the following three different types of substrates: single AlN crystal, AlN on sapphire, and AIN on Si(111). QD density control over th ...

IEEE2019

AlN grown on Si(111) by ammonia-molecular beam epitaxy in the 900-1200 degrees C temperature range

Denis Martin, Nicolas Grandjean, Sebastian Pascal Tamariz Kaufmann

We present a comprehensive study of AlN growth on Si(111) substrate by gas source molecular beam epitaxy with ammonia as nitrogen precursor in the high temperature range. We first demonstrate that the observation of the silicon 7 x 7 surface reconstruction ...

Elsevier2017