Publications de Tania Palmieri

Mahan excitons in room-temperature methylammonium lead bromide perovskites

László Forró, Majed Chergui, Ana Akrap, Endre Horvath, Tania Palmieri, Edoardo Baldini, Márton Kollár

In a seminal paper, Mahan predicted that excitonic bound states can still exist in a semiconductor at electron-hole densities above the insulator-to-metal Mott transition. However, no clear evidence for this exotic quasiparticle, dubbed Mahan exciton, exis ...

Nature Publishing Group2020

Giant Exciton Mott Density in Anatase TiO2

Majed Chergui, Tania Palmieri, Edoardo Baldini

Elucidating the carrier density at which strongly bound excitons dissociate into a plasma of uncorrelated electron-hole pairs is a central topic in the many-body physics of semiconductors. However, there is a lack of information on the high-density respons ...

2020

Nonequilibrium exciton physics in hybrid lead-halide perovskites and anatase titanium dioxide

Tania Palmieri

The strength of the electron-hole interaction in bulk semiconductors is not only determined by the dielectric environment, but also depends on the presence of other quasiparticles - free charge carriers or phonons - that populate the system. In the former ...

EPFL2019

Electron Dynamics in Anatase TiO2 Nanoparticles by Ultrafast Broadband Deep-Ultraviolet Spectroscopy

Majed Chergui, Gerald Auböck, Tania Palmieri, Edoardo Baldini, Enrico Pomarico

The optical bandgap of anatase TiO2 nanoparticles is dominated by bulk absorption bands in the deep-ultraviolet due to strongly bound excitons. These spectral features can be utilized as a sensitive probe of carrier and lattice dynamics inside the TiO2 nan ...

E D P SCIENCES2019

Exciton control in a room temperature bulk semiconductor with coherent strain pulses

Majed Chergui, Tania Palmieri, Edoardo Baldini, Oliviero Cannelli

Controlling the excitonic optical properties of room temperature semiconductors using time-dependent perturbations is key to future optoelectronic applications. The optical Stark effect in bulk and low-dimensional materials has recently shown exciton shift ...

American Association for the Advancement of Science (AAAS)2019

Clocking the Ultrafast Electron Cooling in Anatase Titanium Dioxide Nanoparticles

Majed Chergui, Gerald Auböck, Tania Palmieri, Edoardo Baldini, Enrico Pomarico

2018

Phonon-Driven Selective Modulation of Exciton Oscillator Strengths in Anatase TiO2Nanoparticles

Majed Chergui, Gerald Auböck, Thomas Charles Henry Rossi, Tania Palmieri, Edoardo Baldini, Enrico Pomarico, Malte Oppermann

The way nuclear motion affects electronic responses has become a very hot topic in materials science. Coherent acoustic phonons can dynamically modify optical, magnetic, and mechanical properties at ultrasonic frequencies, with promising applications as se ...

American Chemical Society (ACS)2018

Discovery and room-temperature ultrafast manipulation of strongly bound excitons in anatase TiO2

Majed Chergui, Tania Palmieri, Edoardo Baldini

AMER CHEMICAL SOC2018

The LOUVRE Laboratory: State-of-the-Art Ultrafast Ultraviolet Spectroscopies for Molecular and Materials Science

Majed Chergui, Frank van Mourik, Natalia Nagornova, Lars-Hendrik Mewes, Thomas Charles Henry Rossi, Tania Palmieri, Edoardo Baldini, Malte Oppermann, Benjamin Bauer, Aurelio Oriana

We describe the facilities for ultraviolet studies in the femtosecond to nanosecond time domain. These facilities consist of: i) a set-up for deep-ultraviolet spectroscopy in the 260–380 nm range in both pump and probe pulses for transient absorption/refle ...

2017

Interfacial Electron Injection Probed by a Substrate-Specific Excitonic Signature

Majed Chergui, Gerald Auböck, Thomas Charles Henry Rossi, Tania Palmieri, Edoardo Baldini, Enrico Pomarico, Malte Oppermann

Ultrafast interfacial electron transfer in sensitized solar cells has mostly been probed by visible-to-terahertz radiation, which is sensitive to the free carriers in the conduction band of the semiconductor substrate. Here, we demonstrate the use of deep- ...

2017