Broadband Optical Properties of Atomically Thin PtS2 and PtSe2

Noble transition metal dichalcogenides (TMDCs) such as PtS2 and PtSe2 show significant potential in a wide range of optoelectronic and photonic applications. Noble TMDCs, unlike standard TMDCs such as MoS2 and WS2, operate in the ultrawide spectral range from ultraviolet to mid-infrared wavelengths; however, their properties remain largely unexplored. Here, we measured the broadband (245–3300 nm) optical constants of ultrathin PtS2 and PtSe2 films to eliminate this gap and provide a foundation for optoelectronic device simulation. We discovered their broadband absorption and high refractive index both theoretically and experimentally. Based on first-principle calculations, we also predicted their giant out-of-plane optical anisotropy for monocrystals. As a practical illustration of the obtained optical properties, we demonstrated surface plasmon resonance biosensors with PtS2 or PtSe2 functional layers, which dramatically improves sensor sensitivity by 60 and 30%, respectively.

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Fabrication, optical properties, and applications of twisted two-dimensional materials

Nanophotonics ◽

10.1515/nanoph-2020-0024 ◽

2020 ◽

Vol 9 (7) ◽

pp. 1717-1742

Author(s):

Xiao-Guang Gao ◽

Xiao-Kuan Li ◽

Wei Xin ◽

Xu-Dong Chen ◽

Zhi-Bo Liu ◽

...

Keyword(s):

Optical Properties ◽

Carrier Transport ◽

2D Materials ◽

Twist Angle ◽

Transition Metal Dichalcogenides ◽

Two Dimensional ◽

Research Attention ◽

Wide Range ◽

Metal Dichalcogenides ◽

Optoelectronic Applications

AbstractTwo-dimensional (2D) materials such as graphene, black phosphorus, and transition metal dichalcogenides have attracted significant research attention due to their novel properties and wide range of applications in electronic and optoelectronic devices. In particular, investigation of twist-controlled 2D materials has attracted tremendous attention due to their excellent properties such as smooth heterointerfaces, highly gate-tunable bandgaps, and ultrafast carrier transport. Twist-controlled 2D materials combined with their fascinating electronic structures have also indicated their outstanding potential in electronic and optoelectronic applications. In this review, the recent developments in twisted 2D materials are summarized, covering aspects related to their fabrication, twist angle-dependent optical properties, and optoelectronic applications. The photodetectors and orientation-dependent van der Waals junctions are introduced and discussed systematically. Finally, we deliver a summary and outlook to provide a guideline for the future development of this rapidly growing field.

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Giant Photoluminescence Enhancement and Carrier Dynamics in MoS2 Bilayers with Anomalous Interlayer Coupling

Nanomaterials ◽

10.3390/nano11081994 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1994

Author(s):

Han Li ◽

Yating Ma ◽

Zhongjie Xu ◽

Xiang’ai Cheng ◽

Tian Jiang

Keyword(s):

Optical Properties ◽

Transition Metal Dichalcogenides ◽

Interlayer Coupling ◽

Carrier Dynamics ◽

Probe Signal ◽

Exciton Resonance ◽

Pump Probe ◽

Metal Dichalcogenides ◽

Photoluminescence Enhancement ◽

Probe Measurements

Fundamental researches and explorations based on transition metal dichalcogenides (TMDCs) mainly focus on their monolayer counterparts, where optical densities are limited owing to the atomic monolayer thickness. Photoluminescence (PL) yield in bilayer TMDCs is much suppressed owing to indirect-bandgap properties. Here, optical properties are explored in artificially twisted bilayers of molybdenum disulfide (MoS2). Anomalous interlayer coupling and resultant giant PL enhancement are firstly observed in MoS2 bilayers, related to the suspension of the top layer material and independent of twisted angle. Moreover, carrier dynamics in MoS2 bilayers with anomalous interlayer coupling are revealed with pump-probe measurements, and the secondary rising behavior in pump-probe signal of B-exciton resonance, originating from valley depolarization of A-exciton, is firstly reported and discussed in this work. These results lay the groundwork for future advancement and applications beyond TMDCs monolayers.

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Synergistic vacancy defects and mechanical strain for the modulation of the mechanical, electronic and optical properties of monolayer tungsten disulfide

Physical Chemistry Chemical Physics ◽

10.1039/d0cp06336c ◽

2021 ◽

Vol 23 (10) ◽

pp. 6298-6308

Author(s):

Chan Gao ◽

Xiaoyong Yang ◽

Ming Jiang ◽

Lixin Chen ◽

Zhiwen Chen ◽

...

Keyword(s):

Optical Properties ◽

Transition Metal ◽

Mechanical Strain ◽

Transition Metal Dichalcogenides ◽

Strain Engineering ◽

Tungsten Disulfide ◽

Defect Engineering ◽

Vacancy Defects ◽

Electronic And Optical Properties ◽

Metal Dichalcogenides

The combination of defect engineering and strain engineering for the modulation of the mechanical, electronic and optical properties of monolayer transition metal dichalcogenides (TMDs).

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Second-Order Nonlinear Optical Properties of Monolayer Transition-Metal Dichalcogenides by Computational Analysis

The Journal of Physical Chemistry C ◽

10.1021/acs.jpcc.1c02380 ◽

2021 ◽

Author(s):

Nicholas A. Pike ◽

Ruth Pachter

Keyword(s):

Optical Properties ◽

Transition Metal ◽

Nonlinear Optical ◽

Computational Analysis ◽

Transition Metal Dichalcogenides ◽

Second Order ◽

Nonlinear Optical Properties ◽

Metal Dichalcogenides

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Wrinkle and Near Resonance Effect on the Vibrational and Electronic properties in Compressed Monolayer MoSe2

Physical Chemistry Chemical Physics ◽

10.1039/d0cp06283a ◽

2021 ◽

Author(s):

Yan Liu ◽

Qiang Zhou ◽

Yalan Yan ◽

Liang Li ◽

Jian Zhu ◽

...

Keyword(s):

High Pressure ◽

Optical Properties ◽

Transition Metal ◽

Electronic Properties ◽

Resonance Effect ◽

Transition Metal Dichalcogenides ◽

Effective Technique ◽

Near Resonance ◽

Metal Dichalcogenides

Pressure has been considered as an effective technique to modulate the structural, electronic, and optical properties of transition metal dichalcogenides (TMDs) materials. Here, by performing in situ high pressure Raman,...

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Intriguing electronic structures and optical properties of two-dimensional van der Waals heterostructures of Zr2CT2 (T = O, F) with MoSe2 and WSe2

Journal of Materials Chemistry C ◽

10.1039/c7tc05963a ◽

2018 ◽

Vol 6 (11) ◽

pp. 2830-2839 ◽

Cited By ~ 29

Author(s):

Gul Rehman ◽

S. A. Khan ◽

B. Amin ◽

Iftikhar Ahmad ◽

Li-Yong Gan ◽

...

Keyword(s):

Optical Properties ◽

Material Properties ◽

First Principles ◽

Electronic Structures ◽

Van Der Waals ◽

Transition Metal Dichalcogenides ◽

Two Dimensional ◽

First Principles Calculations ◽

Van Der Waals Heterostructures ◽

Metal Dichalcogenides

Based on (hybrid) first-principles calculations, material properties (structural, electronic, vibrational, optical, and photocatalytic) of van der Waals heterostructures and their corresponding monolayers (transition metal dichalcogenides and MXenes) are investigated.

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THE ELECTRONIC STRUCTURE AT ORGANIC–2D MATERIAL HETEROINTERFACES

Surface Review and Letters ◽

10.1142/s0218625x21400035 ◽

2021 ◽

pp. 2140003

Author(s):

YU LI HUANG ◽

ANDREW THYE SHEN WEE

Keyword(s):

Charge Transfer ◽

Electronic Structures ◽

Transition Metal Dichalcogenides ◽

2D Material ◽

Physical Mechanisms ◽

Wide Range ◽

Fundamental Understanding ◽

Potential Applications ◽

Metal Dichalcogenides ◽

Interfacial Charge

Organic–2D material heterostructures have attracted intensive research interest due to their intriguing properties, with a wide range of potential applications in multifunctional flexible electronic and optoelectronic devices. Central to the realization of such devices is a fundamental understanding of the electronic structures at organic–2D material heterointerfaces. The energy level alignment (ELA) at the interface is of paramount importance because it determines the charge transfer barriers between the two materials in contact. In this paper, we discuss the physical mechanisms determining the ELAs, with special attention on interfacial charge transfer at the heterostructures. We review the current understanding of electronic properties at the heterointerfaces formed by the integration of organics with graphene and 2D transition metal dichalcogenides (TMDs), and conclude with a perspective on the future development of organic–2D material heterostructure.

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Prediction of the structural and electronic properties of MoxTi1−xS2 monolayers via first principle simulations

Nanomaterials and Nanotechnology ◽

10.1177/1847980420955093 ◽

2020 ◽

Vol 10 ◽

pp. 184798042095509

Author(s):

Ankit Kumar Verma ◽

Federico Raffone ◽

Giancarlo Cicero

Keyword(s):

Transition Metal ◽

Electronic Properties ◽

Transition Metal Dichalcogenides ◽

Stable Phase ◽

Two Dimensional ◽

Electron Hole ◽

Effective Electron ◽

Wide Range ◽

Structural And Electronic Properties ◽

Metal Dichalcogenides

Two-dimensional transition metal dichalcogenides have gained great attention because of their peculiar physical properties that make them interesting for a wide range of applications. Lately, alloying between different transition metal dichalcogenides has been proposed as an approach to control two-dimensional phase stability and to obtain compounds with tailored characteristics. In this theoretical study, we predict the phase diagram and the electronic properties of Mo xTi1− xS2 at varying stoichiometry and show how the material is metallic, when titanium is the predominant species, while it behaves as a p-doped semiconductor, when approaching pure MoS2 composition. Correspondingly, the thermodynamically most stable phase switches from the tetragonal to the hexagonal one. Further, we present an example which shows how the proposed alloys can be used to obtain new vertical two-dimensional heterostructures achieving effective electron/hole separation.

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