Publications

Group highlights

At the end of this page, you can find the full list of publications.

Heterostrain-Driven Bandgap Increase in Twisted WS2: A Nanoscale Study

In this study, we fingerprint local electronic properties, thickness, and strain fields in twisted WS2 flakes. Advanced imaging techniques and computational analysis reveal that twisted flakes display non-uniform strain distribution, leading to a remarkable 20% increase in bandgap energy attributed to deformation angle influence. This discovery illuminates twisted 2D materials’ electronic behavior and introduces a novel framework with twistronics implications.

S. E. van Heijst, M. Bolhuis, A. Brokkelkamp, J. J. M. Sangers, S. Conesa-Boj

Advanced Functional Materials 2307893 (2023)

Localized Exciton Anatomy and Band Gap Energy Modulation in One-Dimensional MoS2 Nanostructures

Combining scanning transmission electron microscopy and electron energy-loss spectroscopy reveals localized excitons and spatially-dependent modulation of band gap energy in one-dimensional MoS2. These phenomena are linked to curvature-induced strain fields within the crystal structure. The revealed findings shed light on the intricate relationship between strain, excitonic behavior, and band gap, thereby contributing to the enhancement of nanophotonic and optoelectronic device design.

S. van der Lippe, A. Brokkelkamp, J. Rojo, S. Conesa-Boj

Advanced Functional Materials, 2307610 (2023)

Edge-Induced Excitations in Bi2Te3 from Spatially-Resolved Electron Energy-Gain Spectroscopy

Topological insulators hold immense promise for revolutionary plasmonic tech- quantum computing, terahertz detectors, spintronics. Exploring their potential, we delve into elusive plasmonic resonances, often hidden amidst electronic transitions. By focusing on the energy-gain EELS region, we decode collective excitations in Bi2Te3. A remarkable energy peak at -0.8 eV emerges, intensified along the specimen’s edges. Our methodology reveals novel pathways to investigate electronic properties of nanomaterials from the energy-gain region of EEL spectra.

H. La, A. Brokkelkamp, S. van der Lippe, J. ter Hoeve, J. Rojo, S. Conesa-Boj

Ultramicroscopy 254, 113841 (2023)

Spatially Resolved Band Gap and Dielectric Function in Two-Dimensional Materials from Electron Energy Loss Spectroscopy.

We propose a new method that uses machine learning techniques to accurately determine the bandgap and complex dielectric function of 2D materials with a high spatial resolution of a few nanometers. This approach allows for the automation of processing and interpretation of spectral images obtained from electron energy loss spectroscopy. Overall, this strategy presents a powerful tool for the characterization of 2D materials.

A. Brokkelkamp, J. ter Hoeve, I. Postmes, S. E. van Heijst, L. Maduro, A. V. Davydov, S. Krylyuk, J. Rojo, and S. Conesa-Boj

J. Phys. Chem. A 126, 1255 (2022)

Position-Controlled Fabrication of Vertically-Aligned Mo/MoS2 Core-Shell Nanopillar Arrays.

A new technique is described for creating position-controlled Mo/MoS2 core-shell nanopillars. Metal-Mo nanoparticles are first patterned on a silicon wafer and then used to create the final structure. These nanoparticles have the potential to be used as building blocks for new nanophotonic devices.

L. Maduro, M. Noordam, M. Bolhuis, L. Kuipers, and S. Conesa-Boj

Advanced Functional Materials 32, 2107880 (2022)

Charting the low-loss region in electron energy loss spectroscopy with machine learning.

A new method is described for determining the zero-loss peak (ZLP) in electron energy-loss spectra. Machine learning techniques from particle physics are used to create a model-independent, multidimensional determination of the ZLP with a faithful uncertainty estimate. The method is demonstrated by applying it to spectra from flower-like WS nanostructures.

L. I. Roest, S. E. van Heijst, L. Maduro, J. Rojo, and S. Conesa-Boj

Ultramicroscopy (2021)

Vertically-oriented MoS2 nanosheets for nonlinear optical devices.

This study investigates the growth of v-MoS2 nanosheets by sulfurizing a Mo-metal seed layer. The results show an enhanced nonlinear response in the resulting v-MoS2 nanostructures when compared to horizontal counterparts. The findings lay the foundation for fabricating low-dimensional TMD-based nanostructures for versatile nonlinear nanophotonic devices.

M. Bolhuis, J. Hernández-Rueda, S. E. van Heijst, M. Tinoco Rivas, L. Kuipers and S. Conesa-Boj

Nanoscale, 12, 10491 (2020)

Robust fabrication of large-area in- and out-of-plane cross-section samples of layered materials with ultramicrotomy.

In this study, the feasibility of using ultramicrotomy to prepare samples for TEM analysis is demonstrated. The method is shown to lead to reproducible large-scale production of both in-plane and out-plane cross-section, using bulk vertically oriented MoS2 and WS2 nanosheets as an example.

M. O. Cichocka, M. Bolhuis, S. E. van Heijst and S. Conesa-Boj

ACS Appl. Mater. Interfaces 12 (2020)

Strain-Dependent Edge Structures in MoS2 Layers.

We examine edge strain in MoS2 flakes using TEM, GPA, and EELS. We report that different edge structures produce different levels of strain and that edge curvature affects the type of strain. The study aims to understand the relationship between edge strain and electronic behaviour in MoS2 flakes.

M. T. Rivas, L. Maduro, M. Masaki, E. Okunishi and S. Conesa-Boj

Nano Letters, 17, 7021 (2017)

 

Publications

Nanoscale Strain Mapping in van der Waals Materials from 4D-STEM: Beyond the Planar Configuration
M. Bolhuis, S. E. van Heijst, J. J. M. Sangers, S. Conesa-Boj
Small Science, in press (2023)

Heterostrain-Driven Bandgap Increase in Twisted WS2: A Nanoscale Study
S. E. van Heijst, M. Bolhuis, A. Brokkelkamp, J. J. M. Sangers, S. Conesa-Boj
Advanced Functional Materials 2307893 (2023)

Localized Exciton Anatomy and Band Gap Energy Modulation in One-Dimensional MoS2 Nanostructures
S. van der Lippe, A. Brokkelkamp, J. Rojo, S. Conesa-Boj
Advanced Functional Materials, 2307610 (2023)

Edge-Induced Excitations in Bi2Te3 from Spatially-Resolved Electron Energy-Gain Spectroscopy
H. La, A. Brokkelkamp, S. van der Lippe, J. ter Hoeve, J. Rojo, S. Conesa-Boj
Ultramicroscopy 254, 113841 (2023)

Magnetotransport properties of CrO2 nanowires fabricated by selective area growth
K. Prateek, M. Bolhuis, A. Ben Hamida, D. Scholma, S. Conesa Boj, and J. Aarts
Journal of Physics and Chemistry of Solids 178, 111350 (2023)

Spatially Resolved Band Gap and Dielectric Function in Two-Dimensional Materials from Electron Energy Loss Spectroscopy.
A. Brokkelkamp, J. ter Hoeve, I. Postmes, S. E. van Heijst, L. Maduro, A. V. Davydov, S. Krylyuk, J. Rojo, and S. Conesa-Boj
J. Phys. Chem. A 126, 1255 (2022)

First-Principles Calculation of Optoelectronic Properties in 2D Materials: The Polytypic WS2 Case.
L. Maduro, S. E. van Heijst, and S. Conesa-Boj
ACS Phys. Chem Au 2, 191 (2022)

Position-Controlled Fabrication of Vertically-Aligned Mo/MoS2 Core-Shell Nanopillar Arrays.
L. Maduro, M. Noordam, M. Bolhuis, L. Kuipers, and S. Conesa-Boj
Advanced Functional Materials 32, 2107880 (2022)

Molybdenum nanopillar arrays: Fabrication and engineering.
Louis Maduro, Charles de Boer, Marc Zuiddam, Elvedin Memisevic, and Sonia Conesa-Boj
Physica E Low-dimensional Systems and Nanostructures 134, 114903 (2021)

Charting the low-loss region in electron energy loss spectroscopy with machine learning.
L. I. Roest, S. E. van Heijst, L. Maduro, J. Rojo, and S. Conesa-Boj
Ultramicroscopy (2021)

llluminating the electronic properties of WS2 polytypism with electron microscopy.
S. E. van Heijst, M. Mukai, E. Okunishi, H. Hashiguchi, L. I. Roest, L. Maduro, J. Rojo, and S. Conesa-Boj
Ann. Phys. (Berlin) (2021)

Lock-in ultrafast electron microscopy simultaneously visualizes carrier recombination and interface-mediated trapping.
Mathijs WH Garming, Maarten Bolhuis, Sonia Conesa-Boj, Pieter Kruit, Jacob P Hoogenboom
J. Phys. Chem. Lett. 11, 8880 (2020)

Vertically-oriented MoS2 nanosheets for nonlinear optical devices.
M. Bolhuis, J. Hernández-Rueda, S. E. van Heijst, M. Tinoco Rivas, L. Kuipers and S. Conesa-Boj
Nanoscale, 12, 10491 (2020)

Robust fabrication of large-area in- and out-of-plane cross-section samples of layered materials with ultramicrotomy.
M. O. Cichocka, M. Bolhuis, S. E. van Heijst and S. Conesa-Boj
ACS Appl. Mater. Interfaces 12 (2020)

Metallic Edge States in Zig-Zag Vertically-oriented MoS2 Nanowalls
M. T. Rivas, L. Maduro and S. Conesa-Boj
Scientific Reports, 9 (2019)

Strain-Dependent Edge Structures in MoS2 Layers.
M. T. Rivas, L. Maduro, M. Masaki, E. Okunishi and S. Conesa-Boj
Nano Letters, 17, 7021 (2017)

Towards higher electron mobility in modulation doped GaAs/AlGaAs core shell nanowires.
J. L. Boland, G. Tutuncuoglu, J. Q. Gong, S. Conesa-Boj, C. L Davies, L. M Herz, A. Fontcuberta i Morral, M. B Johnston
Nanoscale, 9, 7839 (2017)

Observation of Conductance Quantization in InSb Nanowire Networks.
E. M. T. Fadaly, H. Zhang, S. Conesa-Boj, D. Car, Ö. Gül, S. R. Plissard, R. L. M. Veld, S. Kölling, L. P. Kouwenhoven, E. P. A. M. Bakkers
Nano Letters, 17, 6511 (2017)

Boosting hole mobility in coherently strained [110]-oriented Ge-Si core-shell nanowires.
S. Conesa-Boj, A. Li, S. Koelling, M. Brauns, J. Ridderbos, T. Nguyen, M. Verheijen, P. Koenraad, F. Zwanenburg and E. P. A. M. Bakkers
Nano Letters, 17, 2259 (2017)

Hard superconducting gap in InSb nanowires.
Ö. Gül, H. Zhang, F. K. de Vries, J. van Veen, K. Zuo, V. Mourik, S. Conesa-Boj, M. P. Nowak, D. J. van Woerkom, M. Quintero-Pérez, M. C. Cassidy, A. Geresdi, S. Kölling, D. Car, S. R. Plissard, E. P. A. M. Bakkers and L. P. Kouwenhoven
Nano Letters, 17, 2690 (2017)

Single-Crystalline Hexagonal Silicon-Germanium.
H. I. T Hauge, S. Conesa-Boj, M. A. Verheijen, S. Kolling and E. P. A. M. Bakkers
Nano Letters, 17, 85 (2017)

InSb Nanowires with Built-In GaxIn1-xSb Tunnel Barrier for Majorana Devices.
D. Car, S. Conesa-Boj, H. Zhang, R. L. M. Op het Veld, M. W. A. de Moor, E. M. T. Fadaly, O. Gul, S. Kolling, S. R. Plissard, V. Toresen, M. T. Wimmer, K. Watanabe, T. Taniguchi, L. P. Kouwenhoven and E. P. A. M. Bakkers
Nano Letters, 17, 721 (2017)

Ballistic superconductivity in semiconductor nanowires
H. Zhang, Ö. Gül, S. Conesa-Boj, M.P. Nowak, M. Wimmer, K. Zuo, V. Mourik, F.K. de Vries, J. van Veen, M.W.A. de Moor, J.D.S. Bommer, D.J. van Woerkom, D. Car, S.R. Plissard, E.P.A.M. Bakkers, M. Quintero-Pérez, M.C. Cassidy, S. Koelling, S. Goswami, K. Watanabe, T. Taniguchi and L.P. Kouwenhoven
Nature Communications 8, 16025 (2017)

Synthesis, morphological and electro-optical characterizations of metal/semiconductor nanowire heterostructures.
M. Glaser, A. Kitzler, A. Johannes, S. Prucnal, H. Potts, S. Conesa-Boj, L. Filipovic, H. Kosina, W. Skorupa, E. Bertagnolli, C. Ronning, A. Fontcuberta i Morral and A. Lugstein
Nano Letters 16, 3507 (2016)

Analysis of the Atomic Layer Deposited Al2O3 field effect passivation in black silicon
G. Von Gastrow, R. Alcubilla, P. Ortega, M. Y.-Koski, S. Conesa-Boj, A. Fontcuberta i Morral and H. Savin
Solar Energy Materials and Solar Cells 142, 29 (2015)

Hexagonal Si Realized
H. I. T Hauge, M. A. Verheijen, S. Conesa-Boj, T. Etzelstorfer, M. Watzinger, D. Kriegner, I. Zardo, C. Fasolato, F. Capitani, P. Postorino, S. Kriegner, A. Li, S. Assali, J. Stangl and E.P.A.M. Bakkers
Nano Letters 15, 5855 (2015)

Quantum dots in the GaAs/AlxGa1-xAs core-shell nanowires: Statistical occurrence as a function of the shell thickness
L. Francaviglia, Y. Fontana, S. Conesa-Boj, G. Tutuncuoglu, L. Duchene, M. B. Tanasescu, F. Matteini and A. Fontcuberta i Morral
Appl. Phys. Lett. 107, 033106 (2015)

Bottom-up engineering of InAs at the nanoscale: from V-shaped nanomembranes to Nanowires
E. Russo-Averchi, G. Tutuncuoglu, A. Dalmau-Mallorqui, I. Canales Mundet, M. de la Mata, D. Ruffer, J. Arbiol, S. Conesa-Boj and A. Fontcuberta i Morral
J. of Crystal Growth 420, 47 (2015)

Cracking the Si shell Growth in Hexagonal GaP-Si Core-Shell Nanowires
S. Conesa-Boj, H. I. T Hauge, M. A. Verheijen, S. Assali, A. Li, E.P.A.M. Bakkers and A. Fontcuberta i Morral
Nano Letters, 15, 2974 (2015)

High Yield of GaAs Nanowire Arrays on Si Mediated by the Pinning and Contact Angle of Ga
E. Russo-Averchi, J. Vukajlovic Plestina, G. Tutuncuoglu, A. Dalmau-Mallorqui, M. de la Mata, D. Ruffer, H. Potts, F. Matteini, J. Arbiol, S. Conesa-Boj and A. Fontcuberta i Morral
Nano Letters 15, 2869 (2015)

Modulation Doping of GaAs/AlGaAs Core-Shell Nanowires with Effective Defect Passivation and High Charge Mobility
J. L. Boland, S. Conesa-Boj, P. Parkinson, G. Tutuncuoglu, F. Matteini, D. Ruffer, H. J. Joyce, L. M. Herz, A. Fontcuberta i Morral and M. B. Johnston
Nano Letters 15, 1336 (2015)

Low ensemble disorder in quantum well tube nanowires
C. L. Davies, P. Parkinson, N. Jiang, J. L. Boland, S. Conesa-Boj, H. H. Tan, C. Jagadish, L. M. Herz and M. B. Johnston
Nanoscale 7, 20531 (2015)

Three-dimensional atom probe analysis of Al segregation and quantum dot formation in GaAs/AlGaAs core-shell nanowires
L. Mancini, Y. Fontana, S. Conesa-Boj, I. Blum, F. Vurpillot, L. Francaviglia, E. Russo-Averchi, M. Heiss, J. Arbiol, A. Fontcuberta i Morral and L. Rigutti
Appl. Phys. Lett. 105, 243106 (2014)

Probing inhomogeneous composition in core/shell nanowires by Raman spectroscopy
F. Amaduzzi, E. Alarcon-Llado, E. Russo-Averchi, F. Matteini, M. Heiss, G. Tutuncuoglu, S. Conesa-Boj, M. de la Mata, J. Arbiol and A. Fontcuberta i Morral
J. Appl. Phys. 116, 184303 (2014)

III-V nanowire arrays: growth and light interaction
M. Heiss, E. Russo-Averchi, A. Dalmau-Mallorqui, G. Tutuncuoglu, F. Matteini, D. Ruffer, S. Conesa-Boj, O. Demichel, E. Alarcon-Llado and A. Fontcuberta i Morral
Nanotechnology 25, 014015 (2014)

Plastic and Elastic Strain Fields in GaAs-Si core-shell Nanowires
S. Conesa-Boj, F. Boioli, E. Russo-Averchi, S. Dunand, M. Heiss, D. Ruffer, N. Wyrsch, C. Ballif, L. Miglio and A. Fontcuberta i Morral
Nano Letters 14, 1859 (2014)

Gold-Free Ternary III-V Antimonide Nanowire Arrays On Silicon: Twin-Free Down To The First Bilayer
S. Conesa-Boj, D. Kriegner, X. Han, S. Plissard, X. Wallart, J. Stangl, A. Fontcuberta i Morral, P. Caroff
Nano Letters 14, 326 (2014)

Three-dimensional magneto-photoluminescence as a probe of the electronic properties of crystal-phase quantum disks in GaAs nanowires.
P. Corfdir, B. Van Hattem, E. Uccelli, S. Conesa-Boj, P. Lefebvre, A. Fontcuberta i Morral and R. T. Phillips
Nano Letters 13, 5303 (2013)

Growth mechanisms and process window for InAs V–shaped nanoscale membranes on Si[001].
E. Russo-Averchi, A. Dalmau-Mallorqui, I. Canales-Mundet, G. Tutuncuoglu, E. Alarcon-Llado, M. Heiss, D. Ruffer, P. Caroff, S. Conesa-Boj and A. Fontcuberta i Morral
Nanotechnology 24, 435603 (2013)

Raman spectroscopy of self-catalyzed GaAs1-xSbx nanowires grown on silicon.
E. Alarcon-Llado, S. Conesa-Boj, X. Wallart, P. Caroff, and A. Fontcuberta i Morral
Nanotechnology 24, 405707 (2013)

Hybrid axial and radial Si-GaAs heterostructures in nanowires.
S. Conesa-Boj, S. Dunand, E. Russo-Averchi, M. Heiss, D. Ruffer, N. Wyrsch, C. Ballif, and A. Fontcuberta i Morral
Nanoscale 5, 9633 (2013)

Exciton localization mechanisms in wurtzite-zinc-blende GaAs nanowires.
A. M. Graham, P. Corfdir, M. Heiss, S. Conesa-Boj, E. Uccelli, A. Fontcuberta i Morral, and R. T. Phillips
Phys. Rev. B 87, 125304 (2013)

Self-assembled quantum dots in a nanowire system for quantum photonics.
M. Heiss, Y. Fontana, A. Gustafsson, G. Wust, C. Magen, D. O’Regan, J. W. Luo, B. Ketterer, S. Conesa-Boj, A. V. Kuhlmann, J. Houel, E. Russo-Averchi, J. R. Morante, M. Cantoni, N. Marzari, J. Arbiol, A. Zunger, R. J. Warburton and A. Fontcuberta i Morral
Nature Materials 12, 439 (2013)

Vertical III-V V-Shaped Nanomembranes Epitaxially Grown on a Patterned Si[001] Substrate and Their Enhanced Light Scattering.
S. Conesa-Boj, E. Russo-Averchi, A. Dalmau-Mallorqui, J. Trevino, E. F. Pecora, Carlo Forestiere, Alex Handin, M. Ek, L. Zweifel, L. Reine Wallenberg, D. Ruffer, M. Heiss, D. Troadec, L. Dal Negro, P. Caroff, and A. Fontcuberta i Morral
ACS Nano 6, 10982 (2012)

Carrier confinement in GaN/AlxGa1-xN nanowire heterostructures.
F. Furtmay, J. Teubert, P. Becker, S. Conesa-Boj, J. R. Morante, A. Chernikov, S. Schafer, S. Chatterjee, J. Arbiol, M. Eickhoff
Physical Review B 84, 205303 (2011)

Direct correlation of atomic structure and optical properties in wurtzite/zinc-blende GaAs nanowire heterostructures
M. Heiss, S. Conesa-Boj, J. Ren, H.-H. Tseng, A. Gali, E. Uccelli, F. Peiro, J. R. Morante, E. Kaxiras, J. Arbiol and A. Fontcuberta i Morral
Physical Review B 83, 045303 (2011)

Defect Formation in Ga-Catalyzed Silicon Nanowires.
S. Conesa-Boj, I. Zardo, S. Estrade, L. Wei, P. J. Alet, P. Roca i Cabarrocas, J. R. Morante, F. Peiro, A. Fontcuberta i Morral and J. Arbiol
Crystal Growth & Design 10, 1534 (2010)

Growth study of indium-catalyzed silicon nanowires by plasma enhanced chemical vapor deposition.
I. Zardo, S. Conesa-Boj, S. Estrade, L. Yu, F. Peiro, P. Roca i Cabarrocas, J. R. Morante, J. Arbiol, A. Fontcuberta i Morral
Applied Physics A 100, 287 (2010)

Single crystalline and core-shell indium-catalyzed germanium nanowires–a systematic thermal CVD growth study.
Y. Xiang, L. Cao, S. Conesa-Boj, S. Estrade, J. Arbiol, F. Peiro, M. Heiss, I. Zardo, Morante J.R., M. L. Brongersma and A. Fontcuberta i Morral
Nanotechnology 20, 245608 (2009)

Plasma-enhanced low temperature growth of silicon nanowires and hierarchical structures by using tin and indium catalysts.
L. Yu, B. O.Donnell, P.-J. Alet, S. Conesa-Boj, F. Peiro , J. Arbiol and P. Roca i Cabarrocas
Nanotechnology 20, 225604 (2009)

Gallium assisted plasma enhanced chemical vapor deposition of silicon nanowires.
I. Zardo, L. Yu, S. Conesa-Boj, S. Estrade, P.-J. Alet, J. Simon, M. Frimmer, P. Roca i Cabarrocas, F. Peiro, J. Arbiol, J. R. Morante and A. Fontcuberta i Morral
Nanotechnology 20, 155602 (2009)

Catalyst-free nanowires with axial InxGa1-xAs/GaAs heterostructures.
M. Heiss, A. Gustafsson, S. Conesa-Boj, F. Peiro, J. R. Morante, G. Abstreiter, J. Arbiol, L. Samuelson and A. Fontcuberta i Morral
Nanotechnology 20, 075603 (2009)

Long Range Epitaxial growth of Prismatic Heterostructures on the Facets of Catalyst-Free GaAs Nanowires.
M. Heigoldt, J. Arbiol, D. Spirkoska, J. M. Rebled, S. Conesa-Boj, G. Abstreiter, F. Peiro, J. R. Morante and A. Fontcuberta i Morral
Journal of Materials Chemistry 19, 840 (2009)

Raman spectroscopy of wurtzite and zinc-blende GaAs nanowires: Polarization dependence, selection rules, and strain effects.
I. Zardo, S. Conesa-Boj, F. Peiro, J. R. Morante, J. Arbiol, E. Uccelli, G. Abstreiter and A. Fontcuberta i Morral
Physical Review B 80, 245324 (2009)

Structural and optical properties of high quality zinc-blende/wurtzite GaAs nanowire heterostructures.
D. Spirkoska, J. Arbiol, A. Gustafsson, S. Conesa-Boj, F. Glas, I. Zardo, M. Heigoldt, M.H. Gass, A. L. Bleloch, S. Estrade, M. Kaniber, J. Rossler, F. Peiro, J. R. Morante, G. Abstreiter, L. Samuelson and A. Fontcuberta i Morral
Physical Review B 80, 245325 (2009)