pulsed electron microscopy; cathodoluminescence; semiconductors; nanotechnology
Tappy Nicolas, Gallo Pascal, Fontcuberta i Morral Anna, Monachon Christian (2022), Boron quantification, concentration mapping and picosecond excitons dynamics in High-Pressure-High-Temperature diamond by cathodoluminescence, in Carbon
, 191, 48-54.
Tappy Nicolas, Fontcuberta i Morral Anna, Monachon Christian (2022), Image shift correction, noise analysis, and model fitting of (cathodo-)luminescence hyperspectral maps, in Review of Scientific Instruments
, 93(5), 053702-053702.
Güniat Lucas, Tappy Nicolas, Balgarkashi Akshay, Charvin Titouan, Lemerle Raphaël, Morgan Nicholas, Dede Didem, Kim Wonjong, Piazza Valerio, Leran Jean-Baptiste, Tizei Luiz H. G., Kociak Mathieu, Fontcuberta i Morral Anna (2022), Nanoscale Mapping of Light Emission in Nanospade-Based InGaAs Quantum Wells Integrated on Si(100): Implications for Dual Light-Emitting Devices, in ACS Applied Nano Materials
, 5(4), 5508-5515.
Amador-Mendez Nuño, Mathieu-Pennober Tiphaine, Vézian Stéphane, Chauvat Marie-Pierre, Morales Magali, Ruterana Pierre, Babichev Andrey, Bayle Fabien, Julien François H., Bouchoule Sophie, Collin Stéphane, Gil Bernard, Tappy Nicolas, Fontcuberta i Morral Anna, Damilano Benjamin, Tchernycheva Maria (2022), Porous Nitride Light-Emitting Diodes, in ACS Photonics
, 9(4), 1256-1263.
Kúkoľová A., Dimitrievska M., Litvinchuk A. P., Ramanandan S. P., Tappy N., Menon H., Borg M., Grundler D., Fontcuberta i Morral A. (2021), Cubic, hexagonal and tetragonal FeGe x phases ( x = 1, 1.5, 2): Raman spectroscopy and magnetic properties, in CrystEngComm
, 23(37), 6506-6517.
K. Sivan Aswathi, Galán-González Alejandro, Di Mario Lorenzo, Tappy Nicolas, Hernández-Ferrer Javier, Catone Daniele, Turchini Stefano, Benito Ana M., Maser Wolfgang K., Steinvall Simon Escobar, Fontcuberta i Morral Anna, Gallant Andrew, Zeze Dagou A., Atkinson Del, Martelli Faustino (2021), Optical properties and carrier dynamics in Co-doped ZnO nanorods, in Nanoscale Advances
, 3(1), 214-222.
Escobar Steinvall Simon, Ghisalberti Lea, Zamani Reza R., Tappy Nicolas, Hage Fredrik S., Stutz Elias Z., Zamani Mahdi, Paul Rajrupa, Leran Jean-Baptiste, Ramasse Quentin M., Craig Carter W., Fontcuberta i Morral Anna (2020), Heterotwin Zn 3 P 2 superlattice nanowires: the role of indium insertion in the superlattice formation mechanism and their optical properties, in Nanoscale
, 12(44), 22534-22540.
Zamani Mahdi, Imbalzano Giulio, Tappy Nicolas, Alexander Duncan T. L., Martí‐Sánchez Sara, Ghisalberti Lea, Ramasse Quentin M., Friedl Martin, Tütüncüoglu Gözde, Francaviglia Luca, Bienvenue Sebastien, Hébert Cécile, Arbiol Jordi, Ceriotti Michele, Fontcuberta i Morral Anna (2020), 3D Ordering at the Liquid–Solid Polar Interface of Nanowires, in Advanced Materials
, 32(38), 2001030-2001030.
Escobar Steinvall Simon, Tappy Nicolas, Ghasemi Masoomeh, Zamani Reza R., LaGrange Thomas, Stutz Elias Z., Leran Jean-Baptiste, Zamani Mahdi, Paul Rajrupa, Fontcuberta i Morral Anna (2020), Multiple morphologies and functionality of nanowires made from earth-abundant zinc phosphide, in Nanoscale Horizons
The main objective of this project is to provide the scientific and technical basis for next generation pulsed electron sources that outperform current technology by several orders of magnitude. Success in this technology will enable the improvement of current electron-excitation microscopy and support the downsizing evolution of the semiconductor industry by enabling a new set of dynamic measurements in production sites, which are currently impossible as it evolves towards sub-20 nm nodes. It will also directly allow progress towards more efficient light emitting diodes and solar cells by enabling direct detection of defects.We are proposing a disruptive technology for pulsed electron emission, based on the photo-excitation of GaN nanostructures. Novel technical capabilities to manufacture and nanostructure GaN have arisen and consolidated over the last decade, making this project possible today. The proposed structures should provide cathodes with quantum efficiencies in the range of 2.5 to10%. Achieving these values would represent an improvement between 250 and 1000 times with respect to current tip pulsing technologies.The next generation of pulsed cathodes will be first optimized by modelling the band structure and field-effect enhancement through tip shape engineering. The cathodes will then be fabricated by top-down fabrication methods and tested in a specially designed chamber. The efficiency and durability of the cathodes will be characterized to further improve the design. Answering the following fundamental questions is paramount to the development of these cathodes:•What GaN-based heterostructure design minimizes the electron work function at the surface of the tip?•What type(s) of defect(s) are produced during the tip structuration process? Do they affect the functionality and/or durability of the cathode?•What is the emission process and does it have an activation period limiting the time resolution?•When these cathodes are integrated into an electron microscope, how does its resolution vary when the number of electrons per pulse is increased? In particular, is there a threshold after which space-charge effects make it worse?•Are the GaN-based cathodes compatible with a constant-wave laser to perform conventional electron microscopy measurements?•How does these cathodes cleanliness affect the obtained band structure, and therefore their ability to emit electrons?• What is the durability of these GaN-based cathodes in terms of stability - in other words what at their degradation mechanisms? Are there procedures to mitigate these mechanisms and improve their lifetime?