A5055823909- Perovskite Materials and Applications
- Quantum Dots Synthesis And Properties
- Luminescence Properties of Advanced Materials
- Semiconductor Quantum Structures and Devices
- Optical properties and cooling technologies in crystalline materials
- Solid-state spectroscopy and crystallography
- 2D Materials and Applications
- Strong Light-Matter Interactions
- Spectroscopy Techniques in Biomedical and Chemical Research
- Innovative Microfluidic and Catalytic Techniques Innovation
- Organic Electronics and Photovoltaics
- Analytical Chemistry and Sensors
- Spectroscopy and Quantum Chemical Studies
- Luminescence and Fluorescent Materials
- Organic Light-Emitting Diodes Research
- Conducting polymers and applications
Swiss Federal Laboratories for Materials Science and Technology
2022-2024
ETH Zurich
2021-2024
École Polytechnique Fédérale de Lausanne
2023
Semiconductor quantum dots have long been considered artificial atoms, but despite the overarching analogies in strong energy-level quantization and single-photon emission capability, their spectrum is far broader than typical atomic lines. Here, by using ab-initio molecular dynamics for simulating exciton-surface-phonon interactions structurally dynamic CsPbBr3 dots, followed single dot optical spectroscopy, we demonstrate that line-broadening these primarily governed coupling of excitons...
Attaining pure single-photon emission is key for many quantum technologies, from optical computing to distribution and imaging. The past 20 years have seen the development of several solid-state emitters, but most them require highly sophisticated techniques (e.g., ultrahigh vacuum growth methods cryostats low-temperature operation). system complexity may be significantly reduced by employing emitters capable working at room temperature. Here, we present a systematic study across ∼170...
The success of the colloidal semiconductor quantum dots (QDs) field is rooted in precise synthetic control QD size, shape, and composition, enabling electronically well-defined functional nanomaterials that foster fundamental science motivate diverse fields applications. While exploitation strong confinement regime has been driving commercial scientific interest InP or CdSe QDs, such a still not thoroughly explored exploited for lead-halide perovskite mainly due to so far insufficient...
Abstract The brightness of an emitter is ultimately described by Fermi’s golden rule, with a radiative rate proportional to its oscillator strength times the local density photonic states. As intrinsic material property, quest for ever brighter emission has relied on states engineering, using dielectric or plasmonic resonators 1,2 . By contrast, much less explored avenue boost strength, and hence rate, collective behaviour termed superradiance. Recently, it was proposed 3 that latter can be...
Nanocrystal superlattices (NC SLs) have long been sought as promising metamaterials, with nanoscale-engineered properties arising from collective and synergistic effects among the constituent building blocks. Lead halide perovskite (LHP) NCs come across outstanding candidates for SL design, they demonstrate light emission, known superfluorescence, in single- multicomponent SLs. Thus far, LHP only assembled single-component SLs or coassembled dielectric NC blocks acting solely spacers between...
Abstract Optimizing the performance of semiconductors in both classical and quantum applications, not only requires a solid understanding elementary excitations such as electrons, holes, or bound electron–hole pairs (excitons), but also their interaction with host material's vibrational states (phonons). Exciton‐phonon coupling is particularly relevant dots (QDs) APbX 3 lead‐halide perovskite (where “A” can be Cs, formamidinium (FA), methylammonium (MA), X Cl, Br, I), new class soft crystal...
The compositional engineering of lead-halide perovskite nanocrystals (NCs) via the A-site cation represents a lever to fine-tune their structural and electronic properties. However, presently available chemical space remains minimal since, thus far, only three cations have been reported favor formation stable NCs, i.e., Cs+, formamidinium (FA), methylammonium (MA). Inspired by recent reports on bulk single crystals with aziridinium (AZ) as cation, we present facile colloidal synthesis...
Self-assembly of colloidal nanocrystals (NCs) holds great promise in the multiscale engineering solid-state materials, whereby atomically engineered NC building blocks are arranged into long-range ordered structures-superlattices (SLs)-with synergistic physical and chemical properties. Thus far, reports have by far focused on single-component binary systems spherical NCs, yielding SLs isostructural with known atomic lattices. Far greater structural space, beyond realm lattices, is...
All-inorganic lead-halide perovskite (LHP) (CsPbX3 , X = Cl, Br, I) quantum dots (QDs) have emerged as a competitive platform for classical light-emitting devices (in the weak light-matter interaction regime, e.g., LEDs and laser), well exploiting strong at room temperature. Many-body interactions correlations among photogenerated exciton complexes play an essential role, example, by determining laser threshold, overall brightness of LEDs, single-photon purity in light sources. Here,...
Lead halide perovskite quantum dots (QDs), the latest generation of colloidal QD family, exhibit outstanding optical properties, which are now exploited as both classical and light sources. Most their rather exceptional properties related to peculiar exciton fine-structure band-edge states, can support unique bright triplet excitons. The degeneracy excitons is lifted with energetic splitting in order millielectronvolts, be resolved by photoluminescence (PL) measurements single QDs at...
The template-assisted self-assembly of CsPbBr 3 nanocrystals into monodisperse supraparticles is presented. Use a droplet-based microfluidic system provides for precise control over supraparticle size.
In lead halide perovskites (APbX3), the effect of A-site cation on optical and electronic properties has initially been thought to be marginal. Yet, evidence beneficial effects solar cell performance light emission is accumulating. Here, we report that A-cation in soft APbBr3 colloidal quantum dots (QDs) controls phonon-induced localization exciton wavefunction. Insights from ab initio molecular dynamics single-particle fluorescence spectroscopy demonstrate anharmonic lattice vibrations...
Colloidal semiconductor nanocrystals have long been considered a promising source of time-correlated and entangled photons via the cascaded emission multiexcitonic states. The spectroscopy such emission, however, is hindered by efficient nonradiative Auger-Meitner decay, rendering states nonemissive. Here we present room-temperature heralded three-photon cascades from triexcitons in giant CsPbBr
Lead halide perovskite quantum dots (QDs), the latest generation of colloidal QD family, exhibit outstanding optical properties which are now exploited as both classical and light sources. Most their rather exceptional related to peculiar exciton fine-structure band-edge states can support unique bright triplet excitons. The degeneracy excitons is lifted with energetic splitting in order millielectronvolts, be resolved by photoluminescence (PL) measurements single QDs at cryogenic...
Interactions between emitters within an ensemble can give rise to cooperative processes that significantly alter the properties of emitted light. One such process is superfluorescence (SF), where excited electric dipoles spontaneously couple coherently and effectively radiate as one macroscopic emitter. It requires low energetic disorder, high temporal coherence oscillator strength, sub-wavelength volumes material be sufficient. Conversely, amplified spontaneous emission (ASE) originates...
Abstract The compositional engineering of lead-halide perovskite nanocrystals (NCs) via the A-site cation represents a lever to fine-tune their structural and electronic properties. However, presently available chemical space remains minimal since, thus far, only three cations have been reported favor formation stable NCs, i.e., Cs + , formamidinium (FA), methylammonium (MA). Inspired by recent reports on bulk single crystals with aziridinium (AZ) as cation, we present facile colloidal...
Abstract The brightness of an emitter is ultimately described by Fermi’s golden rule, with a radiative rate proportional to its oscillator strength times the local density photonic states (LDOS). Since intrinsic material property, quest for ever brighter emission has relied on LDOS engineering, via dielectric or plasmonic resonators 1,2 . In contrast, much less explored avenue boost strength, and hence rate, collective behavior termed superradiance. Recently, it had been proposed 3 that...
Single-photon superradiance in single cesium lead halide perovskite quantum dotsGabriele Raino a, b, Chenglian Zhu Simon Christian Böhme Leon Feld Dmitry Dirin Rainer Mahrt c, Thilo Stöferle Maryna Bodnarchuk Alex Efros d, Peter C Sercel e, Maksym Kovalenko ba Institute of Inorganic Chemistry, Department Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Switzerlandb Laboratory for Thin Films Photovoltaics, Empa – Swiss Federal Laboratories Materials Science Technology, CH-8600...