David Saleta Reig

Institut Català de Nanociència i Nanotecnologia

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Klaas‐Jan Tielrooij

Eindhoven University of Technology

Marianna Sledzinska

Institut Català de Nanociència i Nanotecnologia

C. M. Sotomayor Torres

Institut Català de Nanociència i Nanotecnologia

Sebin Varghese

Institut Català de Nanociència i Nanotecnologia

Jake D. Mehew

Institut Català de Nanociència i Nanotecnologia

Bartłomiej Graczykowski

Adam Mickiewicz University in Poznań

Alexander Block

Institut Català de Nanociència i Nanotecnologia

Alexandros El Sachat

National Centre of Scientific Research "Demokritos"

Pablo Ordejón

Institut Català de Nanociència i Nanotecnologia

Zeila Zanolli

Utrecht University

Cooperative Institutions

Institut Català de Nanociència i Nanotecnologia

Helmholtz-Zentrum Dresden-Rossendorf

Barcelona Institute for Science and Technology

Max Planck Institute for Polymer Research

Centre National de la Recherche Scientifique

Universitat Autònoma de Barcelona

Centre de Recerca Matemàtica

Adam Mickiewicz University in Poznań

Institució Catalana de Recerca i Estudis Avançats

Consejo Superior de Investigaciones Científicas

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Upconversion properties of SrF₂:Yb³⁺,Er³⁺ single crystals

Journal of Materials Chemistry C (2020)

David Saleta Reig Bettina Grauel V. A. Konyushkin А. Н. Накладов П. П. Федоров

We present the excitation power and doping concentration dependent upconversion properties of SrF₂:Yb³⁺,Er³⁺ single crystals. The determined optical properties of this bulk material can serve as benchmark values for cubic-phase nanomaterials.

Photon Upconversion

10.1039/c9tc06591a

Cite

Citations (66)

Thermal conductivity of MoS ₂ polycrystalline nanomembranes

2D Materials (2016)

Marianna Sledzinska Bartłomiej Graczykowski Marcel Placidi David Saleta Reig Alexandros El Sachat

Heat conduction in 2D materials can be effectively engineered by means of controlling nanoscale grain structure. A favorable thermal performance makes these structures excellent candidates for integrated heat management units. Here we show combined experimental and theoretical studies for MoS2 nanosheets in a nanoscale grain-size limit. We report thermal conductivity measurements on 5 nm thick polycrystalline MoS2 by means of 2-laser Raman thermometry. The free-standing, drum-like MoS2 nanomembranes were fabricated using a novel polymer- and residue-free, wet transfer, in which we took advantage of the difference in the surface energies between MoS2 and the growth substrate to transfer the CVD-grown nanosheets. The measurements revealed a strong reduction in the in-plane thermal conductivity down to about 0.73 ± 0.25 . The results are discussed theoretically using finite elements method simulations for a polycrystalline film, and a scaling trend of the thermally conductivity with grain size is proposed.

10.1088/2053-1583/3/3/035016

Cite

Citations (41)

Record Low Thermal Conductivity of Polycrystalline MoS₂ Films: Tuning the Thermal Conductivity by Grain Orientation

ACS Applied Materials & Interfaces (2017)

Marianna Sledzinska Romain Quey Bohayra Mortazavi Bartłomiej Graczykowski Marcel Placidi

We report a record low thermal conductivity in polycrystalline MoS2 obtained for ultrathin films with varying grain sizes and orientations. By optimizing the sulfurization parameters of nanometer-thick Mo layers, five MoS2 films containing a combination of horizontally and vertically oriented grains, with respect to the bulk (001) monocrystal, were grown. From transmission electron microscopy, the average grain size, typically below 10 nm, and proportion of differently oriented grains were extracted. The thermal conductivity of the suspended samples was extracted from a Raman laser-power-dependent study, and the lowest value of thermal conductivity of 0.27 W m-1 K-1, which reaches a similar value as that of Teflon, is obtained in a polycrystalline sample formed by a combination of horizontally and vertically oriented grains in similar proportion. Analysis by means of molecular dynamics and finite element method simulations confirm that such a grain arrangement leads to lower grain boundary conductance. We discuss the possible use of these thermal insulating films in the context of electronics and thermoelectricity.

10.1021/acsami.7b08811

Cite

Citations (46)

A pre-time-zero spatiotemporal microscopy technique for the ultrasensitive determination of the thermal diffusivity of thin films

arXiv (Cornell University) (2022)

Sebin Varghese Jake D. Mehew Alexander Block David Saleta Reig Paweł W. Woźniak

Diffusion is one of the most ubiquitous transport phenomena in nature. Experimentally, it can be tracked by following point spreading in space and time. Here, we introduce a spatiotemporal pump-probe microscopy technique that exploits the residual spatial temperature profile obtained through the transient reflectivity when probe pulses arrive before pump pulses. This corresponds to an effective pump-probe time delay of 13 ns, determined by the repetition rate of our laser system (76 MHz). This pre-time-zero technique enables probing the diffusion of long-lived excitations created by previous pump pulses with nanometer accuracy, and is particularly powerful for following in-plane heat diffusion in thin films. In contrast to existing techniques for quantifying thermal transport it does not require any material input parameters or strong heating. We demonstrate the direct determination of the thermal diffusivities of the layered materials MoSe$_2$ (0.18 cm$^2$/s), WSe$_2$ (0.20 cm$^2$/s), MoS$_2$ (0.35 cm$^2$/s), and WS$_2$ (0.59 cm$^2$/s). This technique paves the way for observing novel nanoscale thermal transport phenomena and tracking diffusion of a broad range of species.

Transient (computer programming)

10.48550/arxiv.2211.04999

Cite

Citations (0)

Unraveling Heat Transport and Dissipation in Suspended MoSe₂ from Bulk to Monolayer

Advanced Materials (2022)

David Saleta Reig Sebin Varghese Roberta Farris Alexander Block Jake D. Mehew

Abstract Understanding heat flow in layered transition metal dichalcogenide (TMD) crystals is crucial for applications exploiting these materials. Despite significant efforts, several basic thermal transport properties of TMDs are currently not well understood, in particular how transport is affected by material thickness and the material's environment. This combined experimental–theoretical study establishes a unifying physical picture of the intrinsic lattice thermal conductivity of the representative TMD MoSe 2 . Thermal conductivity measurements using Raman thermometry on a large set of clean, crystalline, suspended crystals with systematically varied thickness are combined with ab initio simulations with phonons at finite temperature. The results show that phonon dispersions and lifetimes change strongly with thickness, yet the thinnest TMD films exhibit an in‐plane thermal conductivity that is only marginally smaller than that of bulk crystals. This is the result of compensating phonon contributions, in particular heat‐carrying modes around ≈0.1 THz in (sub)nanometer thin films, with a surprisingly long mean free path of several micrometers. This behavior arises directly from the layered nature of the material. Furthermore, out‐of‐plane heat dissipation to air molecules is remarkably efficient, in particular for the thinnest crystals, increasing the apparent thermal conductivity of monolayer MoSe 2 by an order of magnitude. These results are crucial for the design of (flexible) TMD‐based (opto‐)electronic applications.

10.1002/adma.202108352

Cite

Citations (19)

Elastic Properties of Few Nanometers Thick Polycrystalline MoS₂ Membranes: A Nondestructive Study

Nano Letters (2017)

Bartłomiej Graczykowski Marianna Sledzinska Marcel Placidi David Saleta Reig Maciej Kasprzak

The performance gain-oriented nanostructurization has opened a new pathway for tuning mechanical features of solid matter vital for application and maintained performance. Simultaneously, the mechanical evaluation has been pushed down to dimensions way below 1 μm. To date, the most standard technique to study the mechanical properties of suspended 2D materials is based on nanoindentation experiments. In this work, by means of micro-Brillouin light scattering we determine the mechanical properties, that is, Young modulus and residual stress, of polycrystalline few nanometers thick MoS2 membranes in a simple, contact-less, nondestructive manner. The results show huge elastic softening compared to bulk MoS2, which is correlated with the sample morphology and the residual stress.

Nanometre

10.1021/acs.nanolett.7b03669

Cite

Citations (30)

Thickness‐Dependent Elastic Softening of Few‐Layer Free‐Standing MoSe₂

Advanced Materials (2021)

Višnja Babačić David Saleta Reig Sebin Varghese Thomas Vasileiadis Emerson Coy

Abstract Few‐layer van der Waals (vdW) materials have been extensively investigated in terms of their exceptional electronic, optoelectronic, optical, and thermal properties. Simultaneously, a complete evaluation of their mechanical properties remains an undeniable challenge due to the small lateral sizes of samples and the limitations of experimental tools. In particular, there is no systematic experimental study providing unambiguous evidence on whether the reduction of vdW thickness down to few layers results in elastic softening or stiffening with respect to the bulk. In this work, micro‐Brillouin light scattering is employed to investigate the anisotropic elastic properties of single‐crystal free‐standing 2H‐MoSe 2 as a function of thickness, down to three molecular layers. The so‐called elastic size effect, that is, significant and systematic elastic softening of the material with decreasing numbers of layers is reported. In addition, this approach allows for a complete mechanical examination of few‐layer membranes, that is, their elasticity, residual stress, and thickness, which can be easily extended to other vdW materials. The presented results shed new light on the ongoing debate on the elastic size‐effect and are relevant for performance and durability of implementation of vdW materials as resonators, optoelectronic, and thermoelectric devices.

Elasticity

Brillouin zone

Stiffening

10.1002/adma.202008614

Cite

Citations (16)

Microscopic understanding of the in-plane thermal transport properties of 2H transition metal dichalcogenides

Physical review. B./Physical review. B (2024)

Roberta Farris Olle Hellman Zeila Zanolli David Saleta Reig Sebin Varghese

Transition metal dichalcogenides (TMDs) are a class of layered materials that hold great promise for a wide range of applications. Their practical use can be limited by their thermal transport properties, which have proven challenging to determine accurately, both from a theoretical and experimental perspective. We have conducted a thorough theoretical investigation of the thermal conductivity of four common TMDs, MoSe2, WSe2, MoS2, and WS2, at room temperature, to determine the key factors that influence their thermal behavior. We analyze these materials using calculations performed with the program, anharmonic lattice dynamics and the Boltzmann transport equation formalism, as implemented in the temperature-dependent effective potentials method. Within this framework, we analyze the microscopic parameters influencing the thermal conductivity, such as the phonon dispersion and the phonon lifetimes. The aim is to precisely identify the origin of differences in thermal conductivity among these canonical TMD materials. We compare their in-plane thermal properties in monolayer and bulk form, and we analyze how the thickness and the chemical composition affect the thermal transport behavior. We showcase how bonding and the crystal structure influence the thermal properties by comparing the TMDs with silicon, reporting the cases of bulk silicon and monolayer silicene. We find that the interlayer bond type (covalent vs. van der Waals) involved in the structure is crucial in the heat transport. In two-dimensional silicene, we observe a reduction by a factor ∼15 compared to the Si bulk thermal conductivity due to the smaller group velocities and shorter phonon lifetimes. In the TMDs, where the group velocities and the phonon bands do not vary significantly passing from the bulk to the monolayer limit, we do not see as strong a decrease in the thermal conductivity: only a factor 2–3. Moreover, our analysis reveals that differences in the thermal conductivity arise from variations in atomic species, bond strengths, and phonon lifetimes. These factors are closely interconnected and collectively impact the overall thermal conductivity. We inspect each of them separately and explain how they influence the heat transport. We also study artificial TMDs with modified masses, in order to assess how the chemistry of the compounds modifies the microscopic quantities and thus the thermal conductivity. Published by the American Physical Society 2024

10.1103/physrevb.109.125422

Cite

Citations (4)

Thermal conductivity of MoS2 polycrystalline nanosheets

arXiv (Cornell University) (2016)

Marianna Sledzinska Bartłomiej Graczykowski Marcel Placidi David Saleta Reig Alexandros El Sachat

We report a technique for transferring large areas of the CVD-grown, few-layer MoS2 from the original substrate to another arbitrary substrate and onto holey substrates, in order to obtain free-standing structures. The method consists of a polymer- and residue-free, surface-tension-assisted wet transfer, in which we take advantage of the hydrophobic properties of the MoS2. The methods yields better quality transferred layers, with fewer cracks and defects, and less contamination than the widely used PMMA-mediated transfer and allows fabrication of few-layer, fee-standing structures with diameters up to 100 micro-m. We report thermal conductivity measurements by means of contactless Raman thermometry on the so-fabricated samples. The measurements revealed a strong reduction in the in-plane thermal conductivity down to 0.5 W/mK. The results are explained using finite elements method simulations for a polycrystalline film.

10.48550/arxiv.1604.04865

Cite

Citations (1)

One Component Silver-Polystyrene Nanocomposites: The Interplay of Thermoplasmonics and Elastic Mechanical Properties

Bulletin of the American Physical Society (2019)

David Saleta Reig P. Hummel Zuyuan Wang Sabine Rosenfeldt Bart Graczykowski

Polystyrene

Component (thermodynamics)

Source

Cite

Citations (0)