Publications de Nicolas Tappy | EPFL Graph Search

Towards semiconducting nano-engineered photocathodes for electron microscopy applications

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

Light emission properties of mechanical exfoliation induced extended defects in hexagonal boron nitride flakes

Anna Fontcuberta i Morral, Nicolas Tappy

Recently, hexagonal boron nitride (hBN) has become an interesting platform for quantum optics due to its peculiar defect-related luminescence properties. Concomitantly, hBN was established as the ideal insulating support for realizing 2D materials devices, ...

IOP Publishing Ltd2022

Boron quantification, concentration mapping and picosecond excitons dynamics in High-Pressure-High-Temperature diamond by cathodoluminescence

Anna Fontcuberta i Morral, Nicolas Tappy

Diamond is one of the most promising materials for high power and extreme conditions electronics. For this to become a reality, incorporation of active dopants needs to be understood. In this article we demonstrate how cathodoluminescence spectroscopy can ...

2022

Nanoscale Mapping of Light Emission in Nanospade-Based InGaAs Quantum Wells Integrated on Si(100): Implications for Dual Light-Emitting Devices

Anna Fontcuberta i Morral, Jean-Baptiste Leran, Nicolas Tappy, Nicholas Paul Morgan, Raphaël François Lemerle, Wonjong Kim, Akshay Balgarkashi, Titouan Charvin, Didem Dede, Valerio Piazza

III-V semiconductors outperform Si in many optoelectronics applications due to their high carrier mobility, efficient light emission and absorption processes, and the possibility to engineer their band gap through alloying. However, complementing Si techno ...

2022

Deconvolution of Light-Induced Ion Migration Phenomena by Statistical Analysis of Cathodoluminescence in Lead Halide-Based Perovskites

Mohammad Khaja Nazeeruddin, Paul Joseph Dyson, Ulf Anders Hagfeldt, Nicolas Tappy, Erfan Shirzadi

Studying the compositional instability of mixed ion perovskites under light illumination is important to understand the mechanisms underlying their efficiency and stability. However, current techniques are limited in resolution and are unable to deconvolut ...

WILEY2022

Boron-Doped-HPHT-Diamond CL Dataset

Nicolas Tappy

Cathodoluminescence datasets and analysis notebooks accompanying the following publication: https://doi.org/10.1016/j.carbon.2022.01.030 The analysis files rely on the development hyperspy version at the time of release (1.6.1). If compatibility issues a ...

Zenodo2022

Image shift correction, noise analysis, and model fitting of (cathodo-)luminescence hyperspectral maps

Anna Fontcuberta i Morral, Nicolas Tappy

Hyperspectral imaging is an important asset of modern spectroscopy. It allows us to perform optical metrology at a high spatial resolution, for example in cathodoluminescence in scanning electron microscopy. However, hyperspectral datasets present added ch ...

2022

Porous Nitride Light-Emitting Diodes

Anna Fontcuberta i Morral, Nicolas Tappy, Nuno Amador Mendez

A porous InGaN/GaN blue light-emitting diode is demonstrated using selective area sublimation. Transmission electron microscopy reveals that the structure is porous down to the Si substrate; however, the porosity is higher in the GaN buffer, while smaller ...

2022

Accompanying dataset to ACS Appl. Nano Mater. 2022, 5, 4, 5508–5515 : Nanoscale Mapping of Light Emission in Nanospade-Based InGaAs Quantum Wells Integrated on Si(100): Implications for Dual Light-Emitting Devices

Anna Fontcuberta i Morral, Jean-Baptiste Leran, Nicolas Tappy, Nicholas Paul Morgan, Raphaël François Lemerle, Wonjong Kim, Akshay Balgarkashi, Didem Dede, Valerio Piazza

Accompanying dataset containing the raw data and analysis contained in the main publication. This comprises the fitted CL-SEM dataset, the CL-STEM dataset, the CL-SEM presented in the SI and the STEM-EDX linescans. ...

Zenodo2022

Dataset for "Cubic, hexagonal and tetragonal FeGex phases (x = 1, 1.5, 2): Raman spectroscopy and magnetic properties"

Anna Fontcuberta i Morral, Dirk Grundler, Nicolas Tappy, Santhanu Panikar Ramanandan, Anna Kúkol'ová, Mirjana Dimitrievska

Raw data associated to the manuscript “Cubic, hexagonal and tetragonal FeGex phases (x = 1, 1.5, 2): Raman spectroscopy and magnetic properties", CrystEngComm 2021, XXXX, XXX, XXX-XXX There is currently an emerging drive to computational materials design ...

Zenodo2021

Cubic, hexagonal and tetragonal FeGex phases (x = 1, 1.5, 2): Raman spectroscopy and magnetic properties

Anna Fontcuberta i Morral, Dirk Grundler, Nicolas Tappy, Santhanu Panikar Ramanandan, Anna Kúkol'ová, Mirjana Dimitrievska

There is currently an emerging drive towards computational materials design and fabrication of predicted novel materials. One of the keys to developing appropriate fabrication methods is determination of the composition and phase. Here we explore the FeGe ...

2021

Optical properties and carrier dynamics in Co-doped ZnO nanorods

Anna Fontcuberta i Morral, Nicolas Tappy, Simon Robert Escobar Steinvall, Aswathi Kanjampurath Sivan

The controlled modification of the electronic properties of ZnO nanorods via transition metal doping is reported. A series of ZnO nanorods were synthesized by chemical bath growth with varying Co content from 0 to 20 atomic% in the growth solution. Optoele ...

ROYAL SOC CHEMISTRY2021

Hyperspectral fitting using hyperspy

Christian Monachon, Anna Fontcuberta i Morral, Nicolas Tappy

This version includes updates to use weighted PCA in heteroscedastic noise estimation. This set of Jupyter notebooks are used in the analysis of hyperspectral datasets with the hyperspy library. The file "clmap_type-IIB_HPHT_diamond-spikes_removed.hspy" ...

Zenodo2021

Optical properties and carrier dynamics in Co-doped ZnO nanorods (vol 3, pg 214, 2021)

Anna Fontcuberta i Morral, Nicolas Tappy, Simon Robert Escobar Steinvall, Aswathi Kanjampurath Sivan

2021

Facet-driven formation of axial and radial In(Ga)As clusters in GaAs nanowires

Anna Fontcuberta i Morral, Jean-Baptiste Leran, Lucas Güniat, Nicolas Tappy, Martin George Friedl, Wonjong Kim, Santhanu Panikar Ramanandan, Akshay Balgarkashi, Didem Dede

Embedding quantum dots in nanowires (NWs) constitutes one promising building block for quantum photonic technologies. Earlier attempts to grow InAs quantum dots on GaAs nanowires were based on the Stranski-Krastanov growth mechanism. Here, we propose a nov ...

2020

Dataset for "Heterotwin Zn3P2 superlattice nanowires: the role of indium insertion in the superlattice formation mechanism and their optical properties"

Anna Fontcuberta i Morral, Elias Zsolt Stutz, Nicolas Tappy, Reza Zamani, William Craig Carter, Mahdi Zamani, Lea Ghisalberti, Simon Robert Escobar Steinvall, Rajrupa Paul

Raw data associated with the publication "Heterotwin Zn3P2 superlattice nanowires: the role of indium insertion in the superlattice formation mechanism and their optical properties", published in Nanoscale on the 22nd October 2020. ...

Zenodo2020

Multiple morphologies and functionality of nanowires made from earth-abundant zinc phosphide

Thomas La Grange, Anna Fontcuberta i Morral, Elias Zsolt Stutz, Jean-Baptiste Leran, Nicolas Tappy, Reza Zamani, Mahdi Zamani, Simon Robert Escobar Steinvall, Rajrupa Paul

Semiconductors made of earth-abundant elements, such as zinc phosphide, have the potential to substitute less abundant, highly functional compound semiconductors such as InAs or InP. Compound semiconductors in the form of nanowires could revolutionise appl ...

2020

3D Ordering at the Liquid-Solid Polar Interface of Nanowires

Cécile Hébert, Duncan Thomas Lindsay Alexander, Anna Fontcuberta i Morral, Gözde Tütüncüoglu, Nicolas Tappy, Martin George Friedl, Michele Ceriotti, Luca Francaviglia, Giulio Imbalzano, Mahdi Zamani, Lea Ghisalberti, Sara Marti Sanchez

The nature of the liquid-solid interface determines the characteristics of a variety of physical phenomena, including catalysis, electrochemistry, lubrication, and crystal growth. Most of the established models for crystal growth are based on macroscopic t ...

Wiley2020

Facet-driven formation of axial and radial In(Ga)As clusters in GaAs nanowires

Anna Fontcuberta i Morral, Jean-Baptiste Leran, Lucas Güniat, Nicolas Tappy, Martin George Friedl, Nicholas Paul Morgan, Wonjong Kim, Santhanu Panikar Ramanandan, Akshay Balgarkashi, Didem Dede

Raw dataset and image files used for the publication ...

2020

Heterotwin Zn3P2 superlattice nanowires: the role of indium insertion in the superlattice formation mechanism and their optical properties

Anna Fontcuberta i Morral, Elias Zsolt Stutz, Jean-Baptiste Leran, Nicolas Tappy, Reza Zamani, Mahdi Zamani, Lea Ghisalberti, Simon Robert Escobar Steinvall, Rajrupa Paul

Zinc phosphide (Zn3P2) nanowires constitute prospective building blocks for next generation solar cellsdue to the combination of suitable optoelectronic properties and an abundance of the constitutingelements in the Earth’s crust. The generation of periodi ...

2020