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Concept

Cathodoluminescence

Publications associées (27)

Correlating cryo-super resolution radial fluctuations and dual-axis cryo-scanning transmission electron tomography to bridge the light-electron resolution gap

Prabhu Prasad Swain

Visualization of organelles and their interactions with other features in the native cell remains a challenge in modern biology. We have introduced cryo-scanning transmission electron tomography (CSTET), which can ac-cess 3D volumes on the scale of 1 micro ...

Elsevier2023

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

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 and Time-Resolved Transmission Electron Microscopy of Nanoscale Processes

Chengcheng Yan

Observing the fast dynamics of nanoscale systems is crucial in order to understand and ultimately control their behavior. Characterizing these dynamic processes requires techniques with atomic spatial resolution and a temporal resolution that matches the t ...

EPFL2023

Porous Nitride Light-Emitting Diodes

Anna Fontcuberta i Morral, Nicolas Tappy

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

Revealing fundamentals of charge extraction in photovoltaic devices through potentiostatic photoluminescence imaging

Michael Graetzel, Shaik Mohammed Zakeeruddin, Yuhang Liu

The photocurrent density-voltage (J(V)) curve is the fundamental characteristic to assess opto-electronic devices, in particular solar cells. However, it only yields information on the performance inte-grated over the entire active device area. Here, a met ...

ELSEVIER2022

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

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

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

Imaging Nonradiative Point Defects Buried in Quantum Wells Using Cathodoluminescence

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Duncan Thomas Lindsay Alexander, Wei Liu, Wei Liu, Thomas Fjord Kjaersgaard Weatherley

Crystallographic point defects (PDs) can dramatically decrease the efficiency of optoelectronic semiconductor devices, many of which are based on quantum well (QW) heterostructures. However, spatially resolving individual nonradiative PDs buried in such QW ...

AMER CHEMICAL SOC2021

High-Resolution Transmission Electron Microscopy with Bright Microsecond Electron Pulses

Marcel Drabbels, Ulrich Lorenz, Pavel Olshin, Gabriele Bongiovanni

Transmission electron microscopy at atomic-resolution is a crucial tool in a variety of fields, ranging from materials science to biology. [1,2] Fast electron cameras have recently enabled high-speed observations atomic resolution. [3] Moreover, they have ...

2021

Toward Bright Red-Emissive Carbon Dots through Controlling Interaction among Surface Emission Centers

Nikita Tepliakov

Relatively weak red photoluminescence of carbon dots (CDots) is a major challenge on the way to their successful implementation in biological and optoelectronic devices. We present a theoretical analysis of the interaction among the surface emission center ...

2020

Characterization of a time-resolved electron microscope with a Schottky field emission gun

Marcel Drabbels, Ulrich Lorenz, Pavel Olshin

The rapid growth of the field of time-resolved and ultrafast electron microscopy has been accompanied by the active development of new instrumentation. Recently, time-resolved microscopes equipped with a field emission gun have been introduced, demonstrati ...

2020

Method and system for analysis of organic material by auto-cathodoluminescence

Hans Mattias Larsson, Marcin Stefan Zielinski

Analyzing isolated collagen gel samples of a rat-tail and bovine hide, we demonstrated in situ detection of spectrally deconvoluted auto-cathodoluminescence signatures of specific molecular content with precise spatial localization over a maximum field of ...

2020

Microfluidic-based linear-optics label-free imager

Demetri Psaltis

Linear optics based nanoscopy previously reached resolution beyond the diffraction limit, illuminating samples in the visible light regime while allowing light to interact with freely moving metallic nanoparticles. However, the hydrodynamics governing the ...

ROYAL SOC CHEMISTRY2020

Flower-like magnetized photocatalysts accelerating an emerging pollutant removal under indoor visible light and related phenomena

César Pulgarin, Juan Kiwi, Sami Rtimi

This study presents the first evidence for FeOx intra-gap states on Bi2WO6- magnetized materials enhancing the Norfloxacin (NFX) degradation with respect to Bi2WO6 within acceptable times under indoor visible light (< 5 mW/cm(2)). The kinetically faster ph ...

ELSEVIER SCIENCE SA2019

Single-Crystalline γ-Ga2S3 Nanotubes via Epitaxial Conversion of GaAs Nanowires

Anna Fontcuberta i Morral, Nicolas Tappy, Akshay Balgarkashi

Cathodoluminescence scanning electron microscopy (CL-SEM) data and spectrum as decribed in the main text and supporting information to the publication ...

2019

The Quest for Molecular Grippers: Photo-Electric Control of Molecular Gripping Machinery

Jovana Milic

The quest for nanoscale molecular machines has inspired the search for their close relatives, molecular grippers. This path was paved by the development of resorcin[4]arene cavitands and their quinone-based redox-active congeners. In this Concept article, ...

2019

Ultrafast carrier dynamics in III-nitride nanostructures and LED quantum efficiency

Wei Liu, Wei Liu

Since the seminal report about the first Candela- class-brightness InGaN blue light- emitting diodes (LEDs) by Shuji Nakamura et al. in 1994, III-nitride semiconductors have been one of the most important platforms for optoelectronic devices. The achieve ...

EPFL2019

Quantitative intrinsic auto-cathodoluminescence can resolve spectral signatures of tissue-isolated collagen extracellular matrix

Jeffrey Alan Hubbell, Peter Frey, Hans Mattias Larsson, Elif Vardar, Marcin Stefan Zielinski

By analyzing isolated collagen gel samples, we demonstrated in situ detection of spectrally deconvoluted auto-cathodoluminescence signatures of specific molecular content with precise spatial localization over a maximum field of view of 300 mu m. Correlati ...

2019

Probing the Morphology and Evolving Dynamics of 3D Printed Nanostructures Using High-Speed Atomic Force Microscopy

Georg Fantner, Maja Dukic Pjanic, Chen Yang

Focused electron beam induced deposition (FEBID) has been demonstrated as a promising solution for synthesizing truly three-dimensional (3D) nanostructures. However, the lack of morphological feedback during growth complicates further development toward hi ...

Amer Chemical Soc2017