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Last name: TALIERCIO
First name: Thierry
International audience
Time-integrated photoluminescence experiments are used to study the excitonic optical recombinations in wurtzite ZnO∕Zn1−xMgxO single quantum wells of varying widths and magnesium compositions. By comparing experimental results with a variational calculation of excitonic energies, the authors determine the magnitude of the built-in electric...
We report on the optical spectroscopy of a series of ZnO/(Zn, Mg)O quantum wells of different widths, using time-resolved photoluminescence. The samples were grown by molecular beam epitaxy on ZnO templates, themselves deposited on sapphire substrates. The barriers consist of Zn0.78Mg0.22O layers. The presence of large internal electric fields...
We report on polarization-resolved micro-photoluminescence experiments performed on a single GaN/AlN polar quantum dot (QD) grown on Si(111) substrate. We have performed a systematic study of about 50 QDs. The emission of about half of the QD excitons is strongly linearly polarized, up to 90%. Such a polarization is known to be the...
International audience
We present single dot spectroscopy of hexagonal GaN/AlN self‐assembled quantum dots (QDs) grown by MBE along the (0001) axis. The GaN quantum dots are grown on an AlN epilayer on Si (111) substrate, with dot densities between 108 and 1011 cm−2. We study the micro‐photoluminescence spectra of a few quantum dots. In the energy range corresponding...
Wurtzitic ZnO∕(Zn,Mg)O quantum wells grown along the (0001) direction permit unprecedented tunability of the short-range spin exchange interaction. In the context of large exciton binding energies and electron-hole exchange interaction in ZnO, this tunability results from the competition between quantum confinement and giant quantum confined...
We report microphotoluminescence studies of single GaN/AlN quantum dots grown along the (0001) crystal axis by molecular-beam epitaxy on Si(111) substrates. The emission lines exhibit a linear polarization along the growth plane but with varying magnitudes of the polarization degree and with principal polarization axes that do not necessarily...
We report microphotoluminescence studies of single GaN∕AlN quantum dots grown by molecular beam epitaxy on Si(111) substrates. Small groups of emission lines characterize each single dot, with linewidths mostly limited by our experimental setup to 1 or 2meV. By using time-dependent microphotoluminescence, we observe both the continuous and...
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Individual pillars were etched from a sample embedding a single plane of GaN/AlN quantum dots, deposited by molecular beam epitaxy on a sapphire substrate. Pillars with diameters ranging from 0.1 to 5 μm were fabricated by electron-beam lithography and SiCl4 reactive ion etching. The PL from a single pillar could be measured by using a confocal...
International audience
We use the intense, 5-ns-long, excitation pulses provided by the fourth harmonic of a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser to induce a strong high-energy shift of the photoluminescence of a 7.8-nm-wide GaN/Al0.15Ga0.85N single quantum well. We follow the complex relaxation dynamics of the energy and of the intensity of this...
We study by time resolved photoluminescence (TRPL) low N and In content GaInNAs (GINA) alloy layers grown by molecular beam epitaxy on GaAs substrate. The TRPL experiments show the coexistence and the carrier exchanges between bound- and free-exciton states, in this kind of alloy. Temperature dependent experiments demonstrate the thermal...
International audience
We analyze the room temperature photoluminescence properties of several multilayer stackings of GaN/AlN quantum dots. We report drastic differences of emission energies and linewidths between continuous wave and time-resolvedphotoluminescence experiments. In continuous wave experiments, the screening of internal electric fields by accumulation...
We have performed transmittance and piezomodulated transmittance measurements of as-grown GaAsN layers on GaAs substrates. The absorption shows energy an splitting of the ground state transition and a simultaneous increase of the splitting with the increase of the N content. This indicates the presence of a strain, which lifts the light- and...
Continuous-wave, time-integrated, and time-resolved photoluminescence experiments are used to study the excitonic optical recombinations in wurtzite ZnO/Zn0.78Mg0.22O quantum wells of varying widths. By comparing experimental results with a variational calculation of excitonic energies and oscillator strengths, we determine the magnitude...
Low-temperature time-resolved photoluminescence (TR-PL) experiments were used to study the dependence on nitrogen composition of the nature, the energy and the dynamics of radiative carrier recombinations in GaAs1-xNx alloys. Epitaxial layers were grown on [001] GaAs substrates by molecular beam epitaxy using solid sources for group-III and As...
Wurtzite GaN∕AlN quantum dots (QDs) are studied by time-resolved photoluminescence. Careful measurements allow us to reach the regime of a single electron-hole pair per dot, evidenced by a monoexponential decay of the luminescence and a stop of the time-dependent shift of the emission energy. The transition energy and the radiative lifetime of...