scholarly journals Structural stabilities, electronic structures, photocatalysis and optical properties of γ-GeN and α-SnP monolayers: a first-principles study

2021 ◽  
Author(s):  
Liming Liu ◽  
Cuixia Yan ◽  
Lei Gao ◽  
Wei Shangguan ◽  
Jian-Qing Dai ◽  
...  
Keyword(s):  
Energy Band ◽  
Photonic Devices ◽  
Band Gaps ◽  
Photocatalytic Decomposition ◽  
Two Dimensional ◽  
Absorption Coefficients ◽  
Strong Light ◽  
Dimensional Group ◽  
Wide Range ◽  
Two Dimensional Materials

Abstract Exploring two-dimensional materials with excellent photoelectricity properties is of great theoretical significance and practical value for developing new photocatalysts, electronics and photonic devices. Here, using first-principle calculations, we designed and analyzed systematically a series of α, β and γ phase structures of two-dimensional group IV-V monolayers (IV-V, IV = C, Si, Ge, Sn, Pb；V = N, P, As, Sb, Bi), most of them are semiconductors. Among them, γ-GeN and α-SnP monolayers with thermodynamic and kinetic stability (at 300K) have been further studied due to their wide range of energy band gaps (γ-GeN: 2.54 eV, α-SnP:1.34 eV). The two band gaps are greater than the free energy for water splitting (1.23 eV), which are crucial for photocatalytic decomposition of water. The γ-GeN and α-SnP monolayers present excellent photocatalystics properties in PH=0/7 and PH=10 environments, respectively. Moreover, both of the monolayers show strong light absorption coefficients greater than 105 cm-1 in the visible and ultraviolet regions. In addition, it is found that the band edge positions and band gap sizes of γ-GeN and α-SnP monolayers can be regulated by biaxial strain. Benefitting from the wide selection of energy band gaps and high absorption coefficients, the γ-GeN and α-SnP monolayers are the next generation of promising candidate materials for photocatalysts, nanoelectronics and optoelectronics.

Strong coupling in two-dimensional materials-based nanostructures: a review

2022 ◽  
Author(s):  
Ye Ming Qing ◽  
Yongze Ren ◽  
Dangyuan Lei ◽  
Hui Feng Ma ◽  
Tie Jun Cui
Keyword(s):  
Strong Coupling ◽  
Coupling Effect ◽  
Transition Metal Dichalcogenides ◽  
Hybrid Nanostructures ◽  
Two Dimensional ◽  
Strong Light ◽  
Two Dimensional Materials ◽  
Potential Applications ◽  
Metal Dichalcogenides ◽  
Emission Behavior

Abstract Strong interaction between electromagnetic radiation and matter leads to the formation of hybrid light-matter states, making the absorption and emission behavior different from those of the uncoupled states. Strong coupling effect results in the famous Rabi splitting and the emergence of new polaritonic eigenmodes, exhibiting spectral anticrossing behavior and unique energy-transfer properties. In recent years, there has been a rapidly increasing number of works focusing on strong coupling between nanostructures and two-dimensional materials (2DMs), because of the exceptional properties and applications they demonstrate. Here, we review the significant recent advances and important developments of strong light-matter interactions in 2DMs-based nanostructures. We adopt the coupled oscillator model to describe the strong coupling and give an overview of various hybrid nanostructures to realize this regime, including graphene-based nanostructures, black phosphorus-based nanostructures, transition-metal dichalcogenides-based nanostructures, etc. In addition, we discuss potential applications that can benefit from these effects and conclude our review with a perspective on the future of this rapidly emerging field.

scholarly journals Monolayer MoS2 for nanoscale photonics

Nanophotonics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1557-1577 ◽  
Author(s):  
Xianguang Yang ◽  
Baojun Li
Keyword(s):  
Near Infrared ◽  
Transition Metal Dichalcogenides ◽  
Single Layer ◽  
Band Gaps ◽  
Laser Source ◽  
Two Dimensional ◽  
Strong Light ◽  
Metal Dichalcogenides ◽  
Optoelectronic Applications ◽  
Flexible Photodetector

AbstractTransition metal dichalcogenides are two-dimensional semiconductors with strong in-plane covalent and weak out-of-plane interactions, resulting in exfoliation into monolayers with atomically thin thickness. This creates a new era for the exploration of two-dimensional physics and device applications. Among them, MoS2 is stable in air and easily available from molybdenite, showing tunable band-gaps in the visible and near-infrared waveband and strong light-matter interactions due to the planar exciton confinement effect. In the single-layer limit, monolayer MoS2 exhibits direct band-gaps and bound excitons, which are fundamentally intriguing for achieving the nanophotonic and optoelectronic applications. In this review, we start from the characterization of monolayer MoS2 in our group and understand the exciton modes, then explore thermal excitons and band renormalization in monolayer MoS2. For nanophotonic applications, the recent progress of nanoscale laser source, exciton-plasmon coupling, photoluminescence manipulation, and the MoS2 integration with nanowires or metasurfaces are overviewed. Because of the benefits brought by the unique electronic and mechanical properties, we also introduce the state of the art of the optoelectronic applications, including photoelectric memory, excitonic transistor, flexible photodetector, and solar cell. The critical applications focused on in this review indicate that MoS2 is a promising material for nanophotonics and optoelectronics.

scholarly journals Monolayer Graphene Can Emit SHG Waves

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
David N. Carvalho ◽  
Fabio Biancalana ◽  
Andrea Marini
Keyword(s):  
Dirac Equation ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Normal Incidence ◽  
Monolayer Graphene ◽  
Harmonic Waves ◽  
Two Dimensional ◽  
Wide Range ◽  
Two Dimensional Materials ◽  
Breaking Mechanism

AbstractThe usually-held notion that monolayer graphene, a centrosymmetric system, does not allow even-harmonic generation when illuminated at normal incidence is challenged by the discovery of a peculiar effect we term the dynamical centrosymmetry breaking mechanism. This effect results in a global pulse-induced oscillation of the Dirac cones which in turn produces second harmonic waves. We prove that this result can only be found by using the full Dirac equation and show that the widely used semiconductor Bloch equations fail to reproduce this and some other important physics of graphene. These results clear the way for further investigation concerning nonlinear light-matter interactions in a wide range of two-dimensional materials admitting either a gapped or ungapped Dirac-like spectrum.

scholarly journals Photo-Detectors Based on Two Dimensional Materials

2021 ◽  
Author(s):  
Mubashir A. Kharadi ◽  
Gul Faroz A. Malik ◽  
Farooq A. Khanday
Keyword(s):  
Transition Metal ◽  
2D Materials ◽  
Transition Metal Dichalcogenides ◽  
Optoelectronic Devices ◽  
Two Dimensional ◽  
Wide Range ◽  
Two Dimensional Materials ◽  
Photo Detectors ◽  
Metal Dichalcogenides ◽  
Application Specific

2D materials like transition metal dichalcogenides, black phosphorous, silicene, graphene are at the forefront of being the most potent 2D materials for optoelectronic applications because of their exceptional properties. Several application-specific photodetectors based on 2D materials have been designed and manufactured due to a wide range and layer-dependent bandgaps. Different 2D materials stacked together give rise to many surprising electronic and optoelectronic phenomena of the junctions based on 2D materials. This has resulted in a lot of popularity of 2D heterostructures as compared to the original 2D materials. This chapter presents the progress of optoelectronic devices (photodetectors) based on 2D materials and their heterostructures.

scholarly journals Optical Patterning of Two-Dimensional Materials

Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Pavana Siddhartha Kollipara ◽  
Jingang Li ◽  
Yuebing Zheng
Keyword(s):  
Phase Transition ◽  
High Throughput ◽  
State Of The Art ◽  
2D Materials ◽  
Photonic Devices ◽  
Two Dimensional ◽  
Site Specific ◽  
On Demand ◽  
Two Dimensional Materials ◽  
Optical Patterning

Recent advances in the field of two-dimensional (2D) materials have led to new electronic and photonic devices enabled by their unique properties at atomic thickness. Structuring 2D materials into desired patterns on substrates is often an essential and foremost step for the optimum performance of the functional devices. In this regard, optical patterning of 2D materials has received enormous interest due to its advantages of high-throughput, site-specific, and on-demand fabrication. Recent years have witnessed scientific reports of a variety of optical techniques applicable to patterning 2D materials. In this minireview, we present the state-of-the-art optical patterning of 2D materials, including laser thinning, doping, phase transition, oxidation, and ablation. Several applications based on optically patterned 2D materials will be discussed as well. With further developments, optical patterning is expected to hold the key in pushing the frontiers of manufacturing and applications of 2D materials.

scholarly journals Two-dimensional electron gas at the LaAlO3/SrTiO3 inteface with a potential barrier

2016 ◽  
Vol 18 (3) ◽  
pp. 2104-2111 ◽  
Author(s):  
V. A. Stephanovich ◽  
V. K. Dugaev ◽  
J. Barnaś
Keyword(s):  
Energy Band ◽  
Electron Gas ◽  
Tight Binding ◽  
Charge Carriers ◽  
Band Gaps ◽  
Two Dimensional ◽  
Dimensional Electron ◽  
Two Dimensional Electron Gas ◽  
Potential Strength ◽  
Dimensional Electron Gas

We present a tight binding description of electronic properties of the interface between LaAlO3 (LAO) and SrTiO3 (STO). We show that depending on the potential strength, charge carriers (electrons or holes) may form an energy band which is localized at the interface and is within the band gaps of the constituent materials (LAO and STO).

scholarly journals Tunable optical absorption in silicene molecules

2016 ◽  
Vol 4 (31) ◽  
pp. 7387-7390 ◽  
Author(s):  
Junais Habeeb Mokkath ◽  
Udo Schwingenschlögl
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Solar Spectrum ◽  
Great Promise ◽  
Two Dimensional ◽  
Wide Range ◽  
Two Dimensional Materials ◽  
Tunable Band Gap

Two-dimensional materials with a tunable band gap that covers a wide range of the solar spectrum hold great promise for sunlight harvesting.

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