PtSe2 Archives — 2D Research

Metal-Organic Chemical Vapor Deposition of PtSe2. (arXiv:2301.13709v1 [cond-mat.mtrl-sci])

admin2023-02-01T02:29:25+00:00February 1st, 2023|Categories: Publications|Tags: PtSe2|

Platinum diselenide (PtSe2), a novel two-dimensional material from the class of noble-metal dichalcogenide (NMD), has recently received significant attention due to its outstanding properties. PtSe2, which undergoes a semi metallic to semiconductor transition when thinned, offers a band-gap in the infrared range and good air stability. These properties make it a prime active material in optoelectronic and chemical sensing devices. However, a synthesis method that can produce large-scale and reliable high quality PtSe2 is highly sought after. Here, we present PtSe2 growth by metal organic chemical vapor deposition. Films were grown on a variety of centimeter scale substrates and were characterized by Raman, X-ray photoelectron and X-ray diffraction spectroscopy, as well as scanning tunneling microscopy and spectroscopy. Domains within the films are found to be up to several hundred nanometers in size, and atomic scale measurements show their highly ordered crystalline structure. The thickness of homogenous films can be controlled via the growth time. This work provides fundamental guidance for the synthesis and implementation of high quality, large-scale PtSe2 layers, hence offering the key requirement for the implementation of PtSe2 in future electronic devices.

Published in: "arXiv Material Science".

Topological insulating phase arising in transition metal dichalcogenide alloy. (arXiv:2212.05863v1 [cond-mat.mtrl-sci])

admin2022-12-13T02:29:43+00:00December 13th, 2022|Categories: Publications|Tags: PtSe2|

Transition metal dichalcogenides have been the subject of numerous studies addressing technological applications and fundamental issues. Single-layer PtSe2 is a semiconductor with a trivial bandgap, in contrast, its counterpart with 25% of Se atoms substituted by Hg, Pt2HgSe3 (jacutingaite, a naturally occurring mineral), is a 2D topological insulator with a large bandgap. Based on ab-initio calculations, we investigate the energetic stability, and the topological transition in Pt(HgxSe1-x)2 as a function of alloy concentration, and the distribution of Hg atoms embedded in the PtSe2 host. Our findings reveal the dependence of the topological phase with respect to the alloy concentration and robustness with respect distribution of Hg. Through a combination of our ab-initio results and a defect wave function percolation model, we estimate the random alloy concentration threshold for the topological transition to be only 9%. Our results expand the possible search for non-trivial topological phases in random alloy systems.

Published in: "arXiv Material Science".

Effect of the crystallographic c-axis orientation on the tribological properties of the few-layer PtSe2. (arXiv:2209.09128v1 [cond-mat.mtrl-sci])

admin2022-09-20T02:29:38+00:00September 20th, 2022|Categories: Publications|Tags: PtSe2|

Two-dimensional (2D) transition metal dichalcogenides are potential candidates for ultrathin solid-state lubricants in low-dimensional systems owing to their flatness, high in-plane mechanical strength, and low shear interlayer strength. Yet, the effects of surface topography and surface chemistry on the tribological properties of 2D layers are still unclear. In this work, we performed a comparative investigation of nanoscale tribological properties of ultra-thin highly-ordered PtSe2 layers deposited on the sapphire substrates with the in-plane and out-of-plane crystallographic orientation of the PtSe2 c-axis flakes, and also layers consisting of epitaxial PtSe2. PtSe2 c-axis orientation was found to has a moderate impact on the nanotribological and morphological properties of PtSe2, in particular the change in the alignment of the PtSe2 flakes from vertical (VA) to horizontal (HA) led to 1.3 times lower coefficient of friction. This observation was accompanied by an increase in the root-mean-square surface roughness from 1.0 to 1.7 nm for the HA and VA films, respectively. The epitaxial films with larger flakes showed lower friction caused by lowering adhesion when compared to other investigated films, whereas the friction coefficient was similar to films with HA flakes. The observed trends in nanoscale friction is attributed to a different distribution of PtSe2 structure.

Published in: "arXiv Material Science".

Ultrathin Broadband Metasurface Superabsorbers from a van der Waals Semimetal. (arXiv:2208.13269v1 [physics.optics])

admin2022-08-30T04:30:21+00:00August 30th, 2022|Categories: Publications|Tags: Energy, PtSe2|

Metamaterials and metasurfaces operating in the visible and near-infrared (NIR) offer a promising route towards next-generation photodetectors and devices for solar energy harvesting. While numerous metamaterials and metasurfaces using metals and semiconductors have been demonstrated, semimetals-based metasurfaces in the vis-NIR range are notably missing. Here, we experimentally demonstrate a broadband metasurface superabsorber based on large area, semimetallic, van der Waals PtSe2 thin films in agreement with electromagnetic simulations. Our results show that PtSe2 is an ultrathin and scalable semimetal that concurrently possesses high index and high extinction across the vis-NIR range. Consequently, the thin-film PtSe2 on a reflector separated by a dielectric spacer can absorb > 85 % for the unpatterned case and ~97 % for the optimized 2D metasurface in the 400-900 nm range making it one of the strongest and thinnest broadband perfect absorbers to date. Our results present a scalable approach to photodetection and solar energy harvesting, demonstrating the practical utility of high index, high extinction semimetals for nanoscale optics.

Published : "arXiv Mesoscale and Nanoscale Physics".

Ultrathin Broadband Metasurface Superabsorbers from a van der Waals Semimetal. (arXiv:2208.13269v1 [physics.optics])

admin2022-08-30T02:29:44+00:00August 30th, 2022|Categories: Publications|Tags: Energy, PtSe2|

Metamaterials and metasurfaces operating in the visible and near-infrared (NIR) offer a promising route towards next-generation photodetectors and devices for solar energy harvesting. While numerous metamaterials and metasurfaces using metals and semiconductors have been demonstrated, semimetals-based metasurfaces in the vis-NIR range are notably missing. Here, we experimentally demonstrate a broadband metasurface superabsorber based on large area, semimetallic, van der Waals PtSe2 thin films in agreement with electromagnetic simulations. Our results show that PtSe2 is an ultrathin and scalable semimetal that concurrently possesses high index and high extinction across the vis-NIR range. Consequently, the thin-film PtSe2 on a reflector separated by a dielectric spacer can absorb > 85 % for the unpatterned case and ~97 % for the optimized 2D metasurface in the 400-900 nm range making it one of the strongest and thinnest broadband perfect absorbers to date. Our results present a scalable approach to photodetection and solar energy harvesting, demonstrating the practical utility of high index, high extinction semimetals for nanoscale optics.

Published in: "arXiv Material Science".

Momentum-dependent oscillator strength crossover of excitons and plasmons in two-dimensional PtSe2. (arXiv:2203.05088v1 [cond-mat.mtrl-sci])

admin2022-03-11T04:30:38+00:00March 11th, 2022|Categories: Publications|Tags: Energy, PtSe2|

The 1T-phase layered PtX2 chalcogenides has attracted widespread interest due to its thickness dependent metal-semiconductor transition driven by strong interlayer coupling. While the ground state properties of this paradigmatic material system have been widely explored, its fundamental excitation spectrum remains poorly understood. Here we combine first principles calculations with momentum (q) resolved electron energy loss spectroscopy (q-EELS) to study the collective excitations in 1T-PtSe2 from the monolayer limit to the bulk. At finite momentum transfer all the spectra are dominated by two distinct interband plasmons that disperse to higher energy with increasing q. Interestingly, the absence of long-range screening in the two-dimensional (2D) limit, inhibits the formation of long wavelength plasmons. Consequently, in the small-q limit, excitations in monolayer PtSe2 are exclusively of excitonic nature, and the loss spectrum coincides with the optical spectrum. Our work unravels the excited state spectrum of layered 1T-PtSe2 and establishes the qualitatively different momentum dependence of excitons and plasmons in 2D materials.

Published : "arXiv Mesoscale and Nanoscale Physics".

Momentum-dependent oscillator strength crossover of excitons and plasmons in two-dimensional PtSe2. (arXiv:2203.05088v1 [cond-mat.mtrl-sci])

admin2022-03-11T02:29:47+00:00March 11th, 2022|Categories: Publications|Tags: Energy, PtSe2|

The 1T-phase layered PtX2 chalcogenides has attracted widespread interest due to its thickness dependent metal-semiconductor transition driven by strong interlayer coupling. While the ground state properties of this paradigmatic material system have been widely explored, its fundamental excitation spectrum remains poorly understood. Here we combine first principles calculations with momentum (q) resolved electron energy loss spectroscopy (q-EELS) to study the collective excitations in 1T-PtSe2 from the monolayer limit to the bulk. At finite momentum transfer all the spectra are dominated by two distinct interband plasmons that disperse to higher energy with increasing q. Interestingly, the absence of long-range screening in the two-dimensional (2D) limit, inhibits the formation of long wavelength plasmons. Consequently, in the small-q limit, excitations in monolayer PtSe2 are exclusively of excitonic nature, and the loss spectrum coincides with the optical spectrum. Our work unravels the excited state spectrum of layered 1T-PtSe2 and establishes the qualitatively different momentum dependence of excitons and plasmons in 2D materials.

Published in: "arXiv Material Science".

Phonon dynamics and thermal conductivity of PtSe2 thin films: Impact of crystallinity and film thickness on heat dissipation. (arXiv:2111.13395v1 [cond-mat.mtrl-sci])

admin2021-11-29T02:29:59+00:00November 29th, 2021|Categories: Publications|Tags: PtSe2|

We present a comparative investigation of the influence of crystallinity and film thickness on the acoustic and thermal properties of 2D layered PtSe2 thin films of varying thickness (0.6-24 nm) by combining a set of experimental techniques, namely, frequency domain thermo-reflectance, low-frequency Raman and pump-probe coherent phonon spectroscopy. We find a 35% reduction in the cross-plane thermal conductivity of polycrystalline films with thickness larger than 12 nm compared to the crystalline films of the same thickness due to phonon grain boundary scattering. Density functional theory calculations are in good agreement with the experiments and further reveal the ballistic nature of cross-plane heat transport in PtSe2 up to a certain thickness (~20 nm). In addition, our experiments revealed strong interlayer interactions in PtSe2, short acoustic phonon lifetimes in the range of picoseconds, out-of-plane elastic constant C33=31.8 GPa and layer-dependent group velocity ranging from 1340 m/s in bilayer PtSe2 to 1873 m/s in 8 layers of PtSe2. The potential of tuning the lattice cross-plane thermal conductivity of layered 2D materials with the level of crystallinity and the real-time observation of coherent phonon dynamics, which have direct implications on the cooling and transport of electrons, open a new playground for research in 2D thermoelectric devices and provide guidelines for thermal management in 2D electronics.

Published in: "arXiv Material Science".

Exciton‐Dominated Ultrafast Optical Response in Atomically Thin PtSe2

admin2021-11-26T13:21:33+00:00November 26th, 2021|Categories: Publications|Tags: PtSe2|

This work for the first time provides direct observation of ultrafast exciton dynamic in mono-, bi-, and tri-layer platinum diselenide single crystals, a rising 2D material star. It is found that photoinduced modulation of excitons and their thickness dependence dominate overall ultrafast transient spectra in the broadband from visible to the near-infrared edge, confirmed by theoretical calculations. Abstract Strongly bound excitons are a characteristic hallmark of 2D semiconductors, enabling unique light–matter interactions and novel optical applications. Platinum diselenide (PtSe2) is an emerging 2D material with outstanding optical and electrical properties and excellent air stability. Bulk PtSe2 is a semimetal, but its atomically thin form shows a semiconducting phase with the appearance of a band-gap, making one expect strongly bound 2D excitons. However, the excitons in PtSe2 have been barely studied, either experimentally or theoretically. Here, the authors directly observe and theoretically confirm excitons and their ultrafast dynamics in mono-, bi-, and tri-layer PtSe2 single crystals. Steady-state optical microscopy reveals exciton absorption resonances and their thickness dependence, confirmed by first-principles calculations. Ultrafast transient absorption microscopy finds that the exciton dominates the transient broadband response, resulting from strong exciton bleaching and renormalized band-gap-induced exciton shifting. The overall transient spectrum redshifts with increasing thickness as the shrinking band-gap redshifts the exciton resonance. This study provides novel insights into exciton photophysics in platinum dichalcogenides.

Published in: "Small".

Two-dimensional Platinum Diselenide Waveguide-Integrated Infrared Photodetectors. (arXiv:2110.12874v1 [physics.app-ph])

admin2021-10-26T02:29:30+00:00October 26th, 2021|Categories: Publications|Tags: PtSe2|

Low cost, easily integrable photodetectors (PDs) for silicon (Si) photonics are still a bottleneck for photonic integrated circuits (PICs), especially for wavelengths above 1.8 ${mu}$m. Multilayered platinum diselenide (PtSe$_2$) is a semi-metallic two-dimensional (2D) material that can be synthesized below 450${deg}$C. We integrate PtSe$_2$ based PDs directly by conformal growth on Si waveguides. The PDs operate at 1550 nm wavelength with a maximum responsivity of 11 mA/W and response times below 8.4 ${mu}$s. Fourier transform infrared spectroscopy (FTIR) in the wavelength range from 1.25 ${mu}$m to 28 ${mu}$m indicates the suitability of PtSe$_2$ for PDs far into the infrared wavelength range. Our PtSe$_2$ PDs integrated by direct growth outperform PtSe$_2$ PDs manufactured by standard 2D layer transfer. The combination of IR responsivity, chemical stability, selective and conformal growth at low temperatures, and the potential for high carrier mobility, make PtSe$_2$ an attractive 2D material for optoelectronics and PICs.

Published in: "arXiv Material Science".

Transport anomalies in the layered compound BaPt4Se6. (arXiv:2109.13902v1 [cond-mat.str-el])

admin2021-09-29T02:29:38+00:00September 29th, 2021|Categories: Publications|Tags: PtSe2|

We report a layered ternary selenide BaPt4Se6 featuring sesqui-selenide Pt2Se3 layers sandwiched by Ba atoms. The Pt2Se3 layers in this compound can be derived from the Dirac-semimetal PtSe2 phase with Se vacancies that form a honeycomb structure. This structure results in a Pt (VI) and Pt (II) mixed-valence compound with both PtSe6 octahedra and PtSe4 square net coordination configurations. Temperature dependent electrical transport measurements suggest two distinct anomalies: a resistivity crossover, mimic to the metal-insulator (M-I) transition at ~150K, and a resistivity plateau at temperatures below 10K. The resistivity crossover is not associated with any structural, magnetic or charge order modulated phase transitions. Magnetoresistivity, Hall and heat capacity measurements concurrently suggest an existing hidden state below 5K in this system. Angle-resolved photoemission spectroscopy measurements reveal a metallic state and no dramatic reconstruction of the electronic structure up to 200K.

Published in: "arXiv Material Science".

PtSe2/Pt Heterointerface with Reduced Coordination for Boosted Hydrogen Evolution Reaction

admin2021-09-21T13:08:10+00:00September 21st, 2021|Categories: Publications|Tags: Energy, PtSe2|

Ultra-small Pt particles are generated in situ on the surface of PtSe2 nanosheet with Se vacancies for enhanced hydrogen evolution reaction. Abstract PtSe2 is a typical noble metal dichalcogenide (NMD) that holds promising possibility for next-generation electronics and photonics. However, when applied in hydrogen evolution reaction (HER), it exhibits sluggish kinetics due to the insufficient capability of absorbing active species. Here, we construct PtSe2/Pt heterointerface to boost the reaction dynamics of PtSe2, enabled by an in situ electrochemical method. It is found that Se vacancies are induced around the heterointerface, reducing the coordination environment. Correspondingly, the exposed Pt atoms at the very vicinity of Se vacancies are activated, with enhanced overlap with H 1s orbital. The adsorption of H. intermediate is thus strengthened, achieving near thermoneutral free energy change. Consequently, the as-prepared PtSe2/Pt exhibits extraordinary HER activity even superior to Pt/C, with an overpotential of 42 mV at 10 mA cm−2 and a Tafel slope of 53 mV dec−1. This work raises attention on NMDs toward HER and provides insights for the rational construction of novel heterointerfaces.

Published in: "Angewandte Chemie International Edition".

High carrier mobility in single-crystal PtSe2 grown by molecular beam epitaxy on ZnO(0001). (arXiv:2109.08102v1 [cond-mat.mtrl-sci])

admin2021-09-17T02:29:24+00:00September 17th, 2021|Categories: Publications|Tags: Graphene, PtSe2|

PtSe2 is attracting considerable attention as a high mobility two-dimensional material with envisionned applications in microelectronics, photodetection and spintronics. The growth of high quality PtSe2 on insulating substrates with wafer-scale uniformity is a prerequisite for electronic transport investigations and practical use in devices. Here, we report the growth of highly oriented few-layers PtSe2 on ZnO(0001) by molecular beam epitaxy. The crystalline structure of the films is characterized with electron and X-ray diffraction, atomic force microscopy and transmission electron microscopy. The comparison with PtSe2 layers grown on graphene, sapphire, mica, SiO2 and Pt(111) shows that among insulating substrates, ZnO(0001) yields films of superior structural quality. Hall measurements performed on epitaxial ZnO/PtSe2 with 5 monolayers of PtSe2 show a clear semiconducting behaviour and a high mobility in excess of 200 cm2V 1s-1 at room temperature and up to 447 cm2V-1s-1 at low temperature.

Published in: "arXiv Material Science".

PtSe2/Pt heterointerface with reduced coordination for boosted hydrogen evolution reaction

admin2021-08-10T13:10:11+00:00August 10th, 2021|Categories: Publications|Tags: Energy, PtSe2|

PtSe 2 is a typical noble metal dichalcogenide (NMD) that holds promising possibility for next-generation electronics and photonics. However, when applied in hydrogen evolution reaction (HER), it exhibits sluggish kinetics due to the insufficient capability of absorbing active species. Here, we construct PtSe 2 /Pt heterointerface to boost the reaction dynamics of PtSe 2 , enabled by an in-situ electrochemical method. It is found that Se vacancies are induced around the heterointerface, reducing the coordination environment. Correspondingly, the exposed Pt atoms at the very vicinity of Se vacancies are activated, with enhanced overlap with H 1s orbital. The adsorption of H • intermediate is thus strengthened, achieving near thermoneutral free energy change. Consequently, the as-prepared PtSe 2 /Pt exhibits extraordinary HER activity even superior to Pt/C, with an overpotential of 42 mV at 10 mA/cm 2 and a Tafel slope of 53 mV/dec. This work raises attention on NMDs toward HER and provides insights for the rational construction of novel heterointerfaces.

Published in: "Angewandte Chemie International Edition".

Coexistence of negative and positive photoconductivity in few-layer PtSe2 field-effect transistors. (arXiv:2107.09492v1 [cond-mat.mtrl-sci])

admin2021-07-21T02:29:19+00:00July 21st, 2021|Categories: Publications|Tags: PtSe2|

Platinum diselenide (PtSe_2) field-effect transistors with ultrathin channel regions exhibit p-type electrical conductivity that is sensitive to temperature and environmental pressure. Exposure to a supercontinuum white light source reveals that positive and negative photoconductivity coexists in the same device. The dominance of one type of photoconductivity over the other is controlled by environmental pressure. Indeed, positive photoconductivity observed in high vacuum converts to negative photoconductivity when the pressure is rised. Density functional theory calculations confirm that physisorbed oxygen molecules on the PtSe_2 surface act as acceptors. The desorption of oxygen molecules from the surface, caused by light irradiation, leads to decreased carrier concentration in the channel conductivity. The understanding of the charge transfer occurring between the physisorbed oxygen molecules and the PtSe_2 film provides an effective route for modulating the density of carriers and the optical properties of the material.

Published in: "arXiv Material Science".

Precise Layer-Dependent Electronic Structure of MBE-Grown PtSe$_2$. (arXiv:2105.03334v1 [cond-mat.mtrl-sci])

admin2021-05-10T02:29:19+00:00May 10th, 2021|Categories: Publications|Tags: PtSe2|

Two-dimensional (2D) platinum diselenide (PtSe$_2$) has received significant attention for 2D transistor applications due to its high mobility. Here, using molecular beam epitaxy, we investigate the growth of 2D PtSe$_2$ on highly oriented pyrolytic graphite (HOPG) and unveil their electronic properties via X-ray photoelectron spectroscopy, Raman spectra, and scanning tunnelling microscopy/spectroscopy as well as density functional theory (DFT) calculations. PtSe$_2$ adopts a layer-by-layer growth mode on HOPG and shows a decreasing band gap with increasing layer number. For the layer numbers from one to four, PtSe$_2$ has band gaps of $2.0 pm 0.1$, $1.1 pm 0.1$, $0.6 pm 0.1$ and $0.20 pm 0.1$ eV, respectively, and becomes semimetal from the fifth layer. DFT calculations reproduce the layer-dependent evolution of both the band gap and band edges, suggest an indirect band-gap structure, and elucidate the underlying physics at the atomic level.

Published in: "arXiv Material Science".

Correlating Nanocrystalline Structure with Electronic Properties in 2D Platinum Diselenide. (arXiv:2104.03636v1 [cond-mat.mtrl-sci])

admin2021-04-09T02:29:39+00:00April 9th, 2021|Categories: Publications|Tags: PtSe2|

Platinum diselenide (PtSe${_2}$) is a two-dimensional (2D) material with outstanding electronic and piezoresistive properties. The material can be grown at low temperatures in a scalable manner which makes it extremely appealing for many potential electronics, photonics, and sensing applications. Here, we investigate the nanocrystalline structure of different PtSe${_2}$ thin films grown by thermally assisted conversion (TAC) and correlate them with their electronic and piezoresistive properties. We use scanning transmission electron microscopy for structural analysis, X-ray photoelectron spectroscopy (XPS) for chemical analysis, and Raman spectroscopy for phase identification. Electronic devices are fabricated using transferred PtSe${_2}$ films for electrical characterization and piezoresistive gauge factor measurements. The variations of crystallite size and their orientations are found to have a strong correlation with the electronic and piezoresistive properties of the films, especially the sheet resistivity and the effective charge carrier mobility. Our findings may pave the way for tuning and optimizing the properties of TAC-grown PtSe${_2}$ towards numerous applications.

Published in: "arXiv Material Science".

Intercorrelated ferroelectrics in 2D van der Waals materials. (arXiv:2011.10914v1 [cond-mat.mtrl-sci])

admin2020-11-24T02:29:39+00:00November 24th, 2020|Categories: Publications|Tags: InSe, MoS2, PtSe2, SnS2, VS2|

2D intercorrelated ferroelectrics, exhibiting a coupled in-plane and out-of-plane ferroelectricity, is a fundamental phenomenon in the field of condensed-mater physics. The current research is based on the paradigm of bi-directional inversion asymmetry in single-layers, which restricts 2D intercorrelated ferroelectrics to extremely few systems. Herein, we propose a new scheme for achieving 2D intercorrelated ferroelectrics using van der Waals (vdW) interaction, and apply this scheme to a vast family of 2D vdW materials. Using first-principles, we demonstrate that 2D vdW multilayers-for example, BN, MoS2, InSe, CdS, PtSe2, TI2O, SnS2, Ti2CO2 etc.- can exhibit coupled in-plane and out-of-plane ferroelectricity, thus yielding 2D intercorrelated ferroelectricsferroelectric physics. We further predict that such intercorrelated ferroelectrics could demonstrate many distinct properties, for example, electrical full control of spin textures in trilayer PtSe2 and electrical permanent control of valley-contrasting physics in four-layer VS2. Our finding opens a new direction for 2D intercorrelated ferroelectric research.

Published in: "arXiv Material Science".

Defect-induced $4p$-magnetism in layered platinum diselenide. (arXiv:2010.13985v1 [cond-mat.mtrl-sci])

admin2020-10-28T02:29:43+00:00October 28th, 2020|Categories: Publications|Tags: PtSe2|

Platinum diselenide (PtSe$_{2}$) is a recently-discovered extrinsic magnet, with its magnetism attributed to the presence of Pt-vacancies. The host material to these defects itself displays interesting structural and electronic properties, some of which stem from an unusually strong interaction between its layers. To date, it is not clear how the unique intrinsic properties of PtSe$_2$ will affect its induced magnetism. In this theoretical work, we show that the defect-induced magnetism in PtSe$_{2}$ thin films is highly sensitive to: (i) the layer-thickness (ii) defect density, and (iii) substrate choice. These different factors dramatically modify all magnetic properties, including the magnitude of local moments, strength of the coupling, and even nature of the coupling between the moments. We further show that the strong inter-layer interactions are key to understanding these effects. A better understanding of the various influences on magnetism, can enable controllable tuning of the magnetic properties in Pt-based dichalcogenides, which can be used to design novel devices for magnetoelectric and magneto-optic applications.

Published in: "arXiv Material Science".

Multipurpose and Reusable Ultrathin Electronic Tattoos Based on PtSe2 and PtTe2. (arXiv:2010.07534v1 [cond-mat.mtrl-sci])

admin2020-10-16T02:29:37+00:00October 16th, 2020|Categories: Publications|Tags: Graphene, PtSe2|

Wearable bioelectronics with emphasis on the research and development of advanced person-oriented biomedical devices have attracted immense interest in the last decade. Scientists and clinicians find it essential to utilize skin-worn smart tattoos for on-demand and ambulatory monitoring of an individual’s vital signs. Here we report on the development of novel ultrathin platinum-based two-dimensional dichalcogenide (Pt-TMDs) based electronic tattoos as advanced building blocks of future wearable bioelectronics. We made these ultrathin electronic tattoos out of large-scale synthesized platinum diselenide (PtSe2) and platinum ditelluride (PtTe2) layered materials and used them for monitoring human physiological vital signs, such as the electrical activity of the heart and the brain, muscle contractions, eye movements, and temperature. We show that both materials can be used for these applications; yet, PtTe2 was found to be the most suitable choice due to its metallic structure. In terms of sheet resistance, skin-contact, and electrochemical impedance, PtTe2 outperforms state-of-the-art gold and graphene electronic tattoos and performs on par with medical-grade Ag/AgCl gel electrodes. The PtTe2 tattoos show four times lower impedance and almost 100 times lower sheet resistance compared to monolayer graphene tattoos. One of the possible prompt implications of the work is perhaps in the development of advanced human-machine interfaces. To display the application, we built a multi-tattoo system that can easily distinguish eye movement and identify the direction of an individual’s sight.

Published in: "arXiv Material Science".