Publications associées à Electron beam lithography with negative Calixarene resists on dense materials: Taking advantage of proximity effects of increase pattern density

Hybrid organic/metal-oxide shells on semiconductor nanocrystals via colloidal atomic layer deposition

The escalating energy demand and the imperative necessity to reduce the carbon footprint require transformative approaches to energy conversion. Materials chemistry plays a pivotal role in addressing these global challenges by developing novel materials fo ...

EPFL2024

Investigating Non-equilibrium Physics in Wide Bandgap Semiconductors and Quantum Materials via Ultrafast Spectroscopy

Hui-Yuan Chen

This thesis uses femtosecond laser spectroscopy in studying strong correlation in condensed matters that are pertinent to future technology: a wide bandgap perovskite and a quantum material, with the employment of ultrafast time-resolved spectroscopy in th ...

EPFL2024

Colloidal Atomic Layer Deposition on Nanocrystals Using Ligand-Modified Precursors

Raffaella Buonsanti, Anna Loiudice, Petru Pasquale Albertini, Ona Segura Lecina, Coline Marie Agathe Boulanger, Philippe Benjamin Green, Mark Adrian Newton, Krishna Kumar, Jari Leemans

Atomic layer deposition (ALD) is a method to grow thin metal oxide layers on a variety of materials for applications spanning from electronics to catalysis. Extending ALD to colloidally stable nanocrystals promises to combine the benefits of thin metal oxi ...

Amer Chemical Soc2024

Exciton migration in two-dimensional materials

Excitons play an essential role in the optical response of two-dimensional materials. These are bound states showing up in the band gaps of many-body systems and are conceived as quasiparticles formed by an electron and a hole. By performing real-time simu ...

Nature Portfolio2024

Long live(d) CsPbBr3 superlattices: colloidal atomic layer deposition for structural stability

Raffaella Buonsanti, Alexander Nicolas Chen, Philippe Benjamin Green, Victoria Lapointe

Superlattice formation afforded by metal halide perovskite nanocrystals has been a phenomenon of interest due to the high structural order induced in these self-assemblies, an order that is influenced by the surface chemistry and particle morphology of the ...

Royal Soc Chemistry2024

Study of growth-induced point defects and their impact on InGaN-based optoelectronic devices

Yao Chen

GaN exhibits a decomposition tendency for temperatures far below its melting point and common growth temperatures used in metal-organic vapour phase epitaxy (MOVPE).This characteristic is known to be a major obstacle for realising GaN bulk substrate. There ...

EPFL2024

Surface Chemistry Dictates the Enhancement of Luminescence and Stability of InP QDs upon c-ALD ZnO Hybrid Shell Growth

Raffaella Buonsanti, Anna Loiudice, Dragos-Constantin Stoian, Petru Pasquale Albertini, Ona Segura Lecina, Philippe Benjamin Green, Mark Adrian Newton, Jari Leemans

Indium phosphide quantum dots (InP QDs) are a promising example of Restriction of Hazardous Substances directive (RoHS)-compliant light-emitting materials. However, they suffer from low quantum yield and instability upon processing under ambient conditions ...

Amer Chemical Soc2023

Towards semiconducting nano-engineered photocathodes for electron microscopy applications

Nicolas Tappy

The growing field of pulsed electron microscopy (PEM) currently suffers from technical challenges, many of which are related to the inefficiency of present pulsed emitters. In this research, we explore semiconductor photoemitters as a replacement of conven ...

EPFL2023

Quantum engineering and detection of advanced radiation beams

Veronica Leccese

Controlling and shaping radiation beams is fundamental for a better understanding of radiation-matter interaction and advancing experimental techniques for material characterization at high spatial resolution. In particular, the current trend in the miniat ...

EPFL2023

Precise Capillary‐Assisted Nanoparticle Assembly in Reusable Templates

Giovanni Boero, Jürgen Brugger, Olivier Martin, Henry Shao-Chi Yu, Hsiang-Chu Wang, Ana Conde Rubio

Capillary-assisted particle assembly (CAPA) in predefined topographical templates is a scalable method for the precise positioning of nanoscale objects on various surfaces. High-resolution CAPA templates are typically fabricated by expensive electron-beam ...

2022

Scalable fabrication of functional nanostructures on stretchable substrates by capillary-assisted particle assembly and adhesion lithography

Henry Shao-Chi Yu

The fabrication of metallic nanostructures on stretchable substrates enables specific applications that exploit the combination of the nano-scale phenomena and the mechanical tunability of the physical dimensions of the nanostructures. Due to the large dif ...

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

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

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

Investigation in Crystal Growth/Morphology and Interface Engineering of Perovskite Solar Cells by Different Deposition Methods

Nadja Isabelle Desiree Klipfel

A new and promising technology has emerged to compete with traditional silicon photovoltaic semiconductors. The low material and processing costs and high-power conversion efficiencies of organic-inorganic metal halide perovskites make these a promising te ...

EPFL2022

Wafer-scale MoS2 with water-vapor assisted showerhead MOCVD

Andras Kis, Aleksandra Radenovic, Yanfei Zhao, Michal Daniel Macha, Mukeshchand Thakur, Jing Zhang, Mukesh Kumar Tripathi, Hyungoo Ji

Among numerous thin film synthesis methods, metalorganic chemical vapor deposition performed in a showerhead reactor is the most promising one for broad use in scalable and commercially adaptable two-dimensional material synthesis processes. Adapting the m ...

ROYAL SOC CHEMISTRY2022

Ligand Locking on Quantum Dot Surfaces via a Mild Reactive Surface Treatment

Aurélien Bornet, Raffaella Buonsanti, Anna Loiudice, Ona Segura Lecina

At the outermost surface of colloidal QDs are organic surface ligands which dynamically bind and release in solution to control the growth kinetics, control the size/shape of the crystals, passivate surface states, and provide colloidal stability through f ...

2021

Integrated photonics enables continuous-beam electron phase modulation

Rui Ning Wang, Tobias Kippenberg, Junqiu Liu, Arslan Sajid Raja, Guanhao Huang, Yujia Yang

Integrated photonics facilitates extensive control over fundamental light-matter interactions in manifold quantum systems including atoms(1), trapped ions(2,3), quantum dots(4) and defect centres(5). Ultrafast electron microscopy has recently made free-ele ...

NATURE PORTFOLIO2021

Fabrication of plasmonic structures with well-controlled nanometric features: a comparison between lift-off and ion beam etching

Christian Santschi, Olivier Martin, Banafsheh Abasahl

After providing a detailed overview of nanofabrication techniques for plasmonics, we discuss in detail two different approaches for the fabrication of metallic nanostructures based on e-beam lithography. The first approach relies on a negative e-beam resis ...

IOP PUBLISHING LTD2021

Nanopillars Enabling III-V Integration on Si (100) and (111)

Lucas Güniat

The majority of current semiconductor technologies are built on Si (100), such as the CMOS technology, or conventional solar cell devices. III-V semiconductors offer great perspectives given their high carrier mobility and direct band gap. However their in ...

EPFL2021