Publications associées à Low-voltage, high-brightness and deep-red light-emitting electrochemical cells (LECs) based on new ruthenium(II) phenanthroimidazole complexes

III-N blue-emitting epi-structures with high densities of dislocations: Fundamental mechanisms for efficiency improvement and applications

Since the dawn of humanity, human beings seeked to light their surroundings for their well-being, security and development. The efficiency of ancient lighting devices, e.g. oil lamps or candles, was in the order of 0.03-0.04% and jumped to 0.4-0.6% with th ...

EPFL2024

Investigation of room-temperature single-photon emitters in GaN-based materials and GaN/AlN quantum dots

Johann Nicolaï Stachurski

Over the past decade, quantum photonics platforms aiming at harnessing the fundamental properties of single particles, such as quantum superposition and quantum entanglement, have flourished. In this context, single-photon emitters capable of operating at ...

EPFL2024

Persistent enhancement of exciton diffusivity in CsPbBr3 nanocrystal solids

Seryio Saris

In semiconductors, exciton or charge carrier diffusivity is typically described as an inherent material property. Here, we show that the transport of excitons among CsPbBr3 perovskite nanocrystals (NCs) depends markedly on how recently those NCs were occup ...

Amer Assoc Advancement Science2024

Full Solution Process of a Near-Infrared Light-Emitting Electrochemical Cell Based on Novel Emissive Ruthenium Complexes of 1,10-Phenanthroline-Derived Ligands and a Eutectic Alloy as the Top Electrode

Mohammad Khaja Nazeeruddin

Near-infrared luminescent materials have recently received considerable attention for a large number of applications, including in solid-state lighting, as bioimaging agents, as photovoltaic cells, and in the telecommunication industry. By adding diverse e ...

AMER CHEMICAL SOC2023

The nanoscale impact of individual nonradiative point defects on InGaN/GaN quantum wells

Thomas Fjord Kjaersgaard Weatherley

Today's world depends on optoelectronic devices: light-emitting diodes illuminate our houses and backlight the displays on our gadgets, while laser diodes underpin fibre-optic communication. Such optoelectronic devices rely on crystalline semiconductor het ...

EPFL2023

Polariton lasing in AlGaN microring with GaN/AlGaN quantum wells

Jean-François Carlin, Nicolas Grandjean, Raphaël Butté

Microcavity polaritons are strongly interacting hybrid light-matter quasiparticles, which are promising for the development of novel light sources and active photonic devices. Here, we report polariton lasing in the UV spectral range in microring resonator ...

AIP Publishing2023

On the Response Speed of Narrowband Organic Optical Upconversion Devices

Frank Nüesch, Roland Hany, Surendra Babu Anantharaman, Wei-Hsu Hu, Matthias Diethelm

Organic upconversion devices (OUCs) consist of an organic infrared photodetector and an organic visible light-emitting diode (OLED), connected in series. OUCs convert photons from the infrared to the visible and are of use in applications such as process c ...

WILEY-V C H VERLAG GMBH2022

Ultrafast carrier and quasiparticle dynamics in strongly confined perovskite nanoplatelets

Etienne Christophe Socie

Over the past decade, lead halide perovskites (LHPs) have received considerable attention thanks to their impressive optoelectronic properties. Today, LHP-based devices are one of the most efficient single-junction solar cells, with power-conversion effici ...

EPFL2022

Donor-Acceptor-Donor "Hot Exciton" Triads for High Reverse Intersystem Crossing in OLEDs

Anne-Clémence Corminboeuf, Sergio Vela Llausi, Maria Fumanal Quintana, Yanan Zhu

Hot exciton materials have the potential to improve the quantum efficiency of organic light-emitting diodes (OLEDs) by promoting high reversed intersystem crossing (hRISC) between a high-lying triplet (T-n, n >= 2) and a radiative singlet (S-m). In recent ...

WILEY-V C H VERLAG GMBH2022

Optoelectronics based on the spin-valley physics of 2D materials

Juan Francisco Gonzalez Marin

Two-dimensional (2D) materials are atomically thin crystals with exceptional mechanical, electrical and optical properties. Their unique characteristics originating from quantum confinement in the vertical dimension have attracted a strong interest for sci ...

EPFL2022

Deep defects in InGaN LEDs: modeling the impact on the electrical characteristics

Jean-François Carlin, Nicolas Grandjean, Camille Haller

Deep defects have a fundamental role in determining the electro-optical characteristics and in the efficiency of InGaN light-emitting diodes (LEDs). However, modeling their effect on the electrical characteristics of the LED is not straightforward. ...

SPIE-INT SOC OPTICAL ENGINEERING2022

Versatile Electroluminescence Color-Tuning Strategy of an Efficient Light-Emitting Electrochemical Cell (LEC) by an Ionic Additive

Mohammad Khaja Nazeeruddin, Narges Yaghoobi Nia

The color-tuning strategies of solid-state light-emitting devices (ss-LEDs) are mainly focused on engineering molecular structures. In this paper, for the first time, we developed a facile strategy for tuning the electroluminescence (EL) color from orange ...

AMER CHEMICAL SOC2022

Room-temperature electrical control of polarization and emission angle in a cavity-integrated 2D pulsed LED

Andras Kis, Dmitrii Unuchek, Juan Francisco Gonzalez Marin, Fedele Tagarelli, Cheol Yeon Cheon, Zhe Sun

Devices based on two-dimensional (2D) semiconductors hold promise for the realization of compact and versatile on-chip interconnects between electrical and optical signals. Although light emitting diodes (LEDs) are fundamental building blocks for integrate ...

Nature Research2022

Long-Term, Single-Molecule Imaging of Proteins in Live Cells with Photoregulated Fluxional Fluorophores

Pablo Rivera Fuentes, Annabell Martin, Adam Miklos Eördögh

Single-molecule localization microscopy (SMLM) can reveal nanometric details of biological samples, but its high phototoxicity hampers long-term imaging in live specimens. A significant part of this phototoxicity stems from repeated irradiations that are n ...

WILEY-V C H VERLAG GMBH2022

Single-Mode Emission in InP Microdisks on Si Using Au Antenna

Kirsten Emilie Moselund, Anna Fischer

An important building block for on-chip photonic applications is a scaled emitter. Whispering gallery mode cavities based on III-Vs on Si allow for small device footprints and lasing with low thresholds. However, multimodal emission and wavelength stabilit ...

AMER CHEMICAL SOC2022

Defects in III-N LEDs: experimental identification and impact on electro-optical characteristics

Jean-François Carlin, Nicolas Grandjean, Mauro Mosca, Camille Haller

III-N light-emitting-diodes (LEDs) are subject of intense investigations, thanks to their high efficiency and great reliability. The quality of the semiconductor material has a significant impact on the electro-optical performance of LEDs: for this reason, ...

SPIE-INT SOC OPTICAL ENGINEERING2022

Luminescent, porous, metal-organic crystals: Design, synthesis, and applications

Fatmah Ebrahim

The work presented in this thesis is focused on the design and discovery of new luminescent, porous, crystalline materials for targeted applications. In particular, we focus on luminescent Metal-Organic Frameworks (MOFs) and Organic Molecules of Intrinsic ...

EPFL2020

Resonant Band-Edge Emissive States in Strongly Confined CsPbBr3 Perovskite Nanoplatelets

Jacques-Edouard Moser, Etienne Christophe Socie, Aaron Tomas Terpstra, Brener Rodrigo De Carvalho Vale

Strongly confined, fully inorganic cesium lead halide perovskite nanocrystals are of great promise for light-emitting devices in the blue spectral range owing to their high photoluminescence quantum yields. A combination of broadband fluorescence up-conver ...

2021

Nano-emitting Heterostructures Violate Optical Reciprocity and Enable Efficient Photoluminescence in Halide-Segregated Methylammonium-Free Wide Bandgap Perovskites

Christophe Ballif, Quentin Thomas Jeangros, Peter Joseph Fiala, Chien-Jen Yang, Pietro Caprioglio, Christian Michael Wolff

This work investigates halide segregation in methylammonium-free wide bandgap perovskites by photoluminescence quantum yield (PLQY) and advanced electron microscopy techniques. Our study reveals how the formation of nano-emitting low-energy domains embedde ...

AMER CHEMICAL SOC2021

Ion and Trap Induced Dynamic Phenomena in Salt Semiconductor Devices

Matthias Diethelm

State-of-the-art organic light-emitting diodes (OLEDs) used in commercial display technology are complex multilayer structures. In contrast, the light-emitting electrochemical cell (LEC) can be built from a single emissive layer sandwiched between two elec ...

EPFL2021