Publications associées à Free-Carrier-Compensated Charged Domain Walls Produced with Super-Bandgap Illumination in Insulating Ferroelectrics

Plasmonic Nanostructures for Photocatalysis: Material, Photonic and Electronic Effects

Plasmonic photochemistry has a large potential to replace energy-intensive chemical processes with low-temperature, low-pressure light-driven chemical reactions. Plasmonic nanostructures have emerged as promising photocatalysts with exceptional and tunable ...

EPFL2024

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

In situ construction of graphdiyne based heterojunctions by a deprotection-free approach for photocatalytic hydrogen generation

Cong Wang, Jian Li

Graphdiyne (GDY) with a direct bandgap, high charge carrier mobility, and ordered pore structure, is considered an excellent matrix for the construction of heterojunction photocatalysts. However, the traditional fabrication methods for GDY-based heterojunc ...

Royal Society of Chemistry2023

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

Synthesis and properties of heterostructures in nanowires and 2-D materials

Akshay Balgarkashi

Modern solid-state devices were made possible by the discovery of semiconductor heterostructures. Heterostructures offer the ability to fabricate low-dimensional nanostructures such as quantum dots which can restrain carriers in all three-directions. Quant ...

EPFL2022

Phase-Pure Quasi-2D Perovskite by Protonation of Neutral Amine

Mohammad Khaja Nazeeruddin, Marc Dessimoz, Hiroyuki Kanda, Cansu Igci, Hobeom Kim, So-Min Yoo

Phase control of low-dimensional metal-halide perovskites (LDPs) greatly affects their optoelectronic properties, and phase-pure LDPs are desirable to achieve efficient perovskite optoelectronic devices such as solar cells and light-emitting diodes. Herein ...

AMER CHEMICAL SOC2021

Novel Interfacial Characterization and Surface Engineering in Semiconductor Electrodes for Optimized Solar Fuel Production

Yongpeng Liu

Harvesting sunlight, the ultimate renewable power source, in a cost-effective way has been long recognized as a necessary route to meet the global energy challenges. Solar energy can be transformed into electricity by means of photovoltaic devices to suppl ...

EPFL2021

Synthesis of NIR-Absorbing Squaraine Dyes and their Use in Organic Upconversion Devices

Karen Verena Strassel

Squaraines are organic dyes showing the advantages of a simple synthesis, high absorption coefficients and tunable bandgaps from the visible to the near-infrared (NIR) region. Their molecular structure is based on a polymethine chain and a donor-acceptor-d ...

EPFL2021

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

Reducing Amplified Spontaneous Emission Threshold in CsPbBr3 Quantum Dot Films by Controlling TiO2 Compact Layer

Mohammad Khaja Nazeeruddin

Amplified spontaneous emission (ASE) threshold in CsPbBr3 quantum dot films is systematically reduced by introducing high quality TiO2 compact layer grown by atomic-layer deposition. Uniform and pinhole-free TiO2 films of thickness 10, 20 and 50 nm are use ...

2020

Remote Doping of Scalable Nanowire Branches

Anna Fontcuberta i Morral, Lucas Güniat, Martin George Friedl, Nicholas Paul Morgan, Wonjong Kim, Didem Dede

Selective-area epitaxy provides a path toward high crystal quality, scalable, complex nanowire networks. These high-quality networks could be used in topological quantum computing as well as in ultrafast photodetection schemes. Control of the carrier densi ...

2020

Optoelectronic Properties of Layered Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Yonghui Lee, Tom Theodorus Antonius Lummen, Kyung Taek Cho, Sanghyun Paek

Herein, the optoelectronic properties of interface-engineered perovskite 2D|3D-heterojunction structure solar cells are reported. The reciprocity theorem is applied to determine the maximum open-circuit voltage (V-oc) the device can deliver under solar ill ...

2019

D35-TiO2 nano-crystalline film as a high performance visible-light photocatalyst towards the degradation of bis-phenol A

Ulf Anders Hagfeldt, Lin Yang, Xue Bai

Dye-sensitized photocatalytic suspension system for wastewater treatment is still limited in practice due to particle aggregation, fast charge carrier recombination, poor stability and recycling issue. In this study, we combine TiO2 nano-crystalline film w ...

ELSEVIER SCIENCE SA2019

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

Photocatalytic Performance of CuxO/TiO2 Deposited by HiPIMS on Polyester under Visible Light LEDs: Oxidants, Ions Effect, and Reactive Oxygen Species Investigation

Sami Rtimi

In the present study, we propose a new photocatalytic interface prepared by high-power impulse magnetron sputtering (HiPIMS), and investigated for the degradation of Reactive Green 12 (RG12) as target contaminant under visible light light-emitting diodes ( ...

2019

Semiconducting van der Waals Interfaces as Artificial Semiconductors

Helmuth Berger, Evgeniy Ponomarev

Recent technical progress demonstrates the possibility of stacking together virtually any combination of atomically thin crystals of van der Waals bonded compounds to form new types of heterostructures and interfaces. As a result, there is the need to unde ...

2018

Low threshold and efficient multiple exciton generation in halide perovskite nanocrystals

Michael Graetzel, Nripan Mathews, Qiang Xu, Mingjie Li

Multiple exciton generation (MEG) or carrier multiplication, a process that spawns two or more electron-hole pairs from an absorbed high-energy photon (larger than two times bandgap energy E-g, is a promising way to augment the photocurrent and overcome th ...

Nature Publishing Group2018

Photophysics behind highly luminescent two-dimensional hybrid perovskite (CH3(CH2)2NH3)2(CH3NH3)2Pb3Br10 thin films

Anna Fontcuberta i Morral, Luca Francaviglia, Pablo Romero Gómez

Two-dimensional (2D) Ruddlesden–Popper perovskites have emerged as a new class of hybrid materials with high photoluminescence and improved stability compared to their three-dimensional (3D) counterparts. Studies of the photophysics of these new 2D perovsk ...

Royal Society of Chemistry2018

Energy and Charge Transfer Cascade in Methylammonium Lead Bromide Perovskite Nanoparticle Aggregates

Jacques-Edouard Moser, Joël Teuscher, Marine Eva Fedora Bouduban, Andrés Burgos Caminal, Rachele Ossola

Highly photoluminescent hybrid lead halide perovskite nanoparticles have recently attracted a wide interest in the context of high-stake applications, such as light emitting diodes (LEDs), light emitting transistors and lasers. In addition, they constitute ...

Royal Soc Chemistry2017