Measuring the Exciton Binding Energy: Learning from a Decade of Measurements on Halide Perovskites and Transition Metal Dichalcogenides DOI Creative Commons
Kameron R. Hansen, John Colton, Luisa Whittaker‐Brooks

et al.

Advanced Optical Materials, Journal Year: 2023, Volume and Issue: 12(3)

Published: Oct. 22, 2023

Abstract The exciton binding energy ( E b ) is a key parameter that governs the physics of many optoelectronic devices. At their best, trustworthy and precise measurements challenge theoreticians to refine models, are driving force in advancing understanding material system, lead efficient device design. worst, inaccurate astray, sow confusion within research community, hinder improvements by leading poor designs. This review article seeks highlight pros cons different measurement techniques used determine , namely, temperature‐dependent photoluminescence, resolving Rydberg states, electroabsorption, magnetoabsorption, scanning tunneling spectroscopy, fitting optical absorption. Due numerous conflicting values reported for halide perovskites (HP) transition metal dichalcogenides (TMDC) monolayers, an emphasis placed on highlighting these attempt reconcile variance between techniques. It argued experiments with clearest indicators agreement following values: ≈350–450 meV TMDC monolayers SiO 2 vacuum, ≈150–200 hBN‐encapsulated ≈200–300 common lead‐iodide 2D HPs, ≈10 methylammonium iodide.

Language: Английский

Bright and Efficient Light‐Emitting Devices Based on 2D Transition Metal Dichalcogenides DOI
Tanveer Ahmed, Jiajia Zha, Kris K. H. Lin

et al.

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(31)

Published: Feb. 20, 2023

Abstract 2D monolayer transition metal dichalcogenides (TMDCs) show great promise for the development of next‐generation light‐emitting devices owing to their unique electronic and optoelectronic properties. The dangling‐bond‐free surface direct‐bandgap structure TMDCs allow near‐unity photoluminescence quantum efficiencies. excellent mechanical optical characteristics offer potential fabricate TMDC‐based diodes (LEDs) featuring good flexibility transparency. Great progress has been made in fabrication bright efficient LEDs with varying device structures. In this review, aim is provide a comprehensive summary state‐of‐the‐art construction based on TMDCs. After brief introduction research background, preparation used briefly discussed. requirements corresponding challenges achieve are introduced. Thereafter, various strategies enhance brightness described. Following that, carrier‐injection schemes enabling along performance summarized. Finally, future prospects regarding accomplishment TMDC‐LEDs ultimate efficiency

Language: Английский

Citations

39
Tunable interlayer excitons and switchable interlayer trions via dynamic near-field cavity DOI Creative Commons
Y. M. Koo, Hyeongwoo Lee, Tatiana Ivanova

et al.

Light Science & Applications, Journal Year: 2023, Volume and Issue: 12(1)

Published: March 3, 2023

Abstract Emerging photo-induced excitonic processes in transition metal dichalcogenide (TMD) heterobilayers, e.g., interplay of intra- and inter-layer excitons conversion to trions, allow new opportunities for ultrathin hybrid photonic devices. However, with the associated large degree spatial heterogeneity, understanding controlling their complex competing interactions TMD heterobilayers at nanoscale remains a challenge. Here, we present an all-round dynamic control interlayer-excitons -trions WSe 2 /Mo 0.5 W Se heterobilayer using multifunctional tip-enhanced photoluminescence (TEPL) spectroscopy <20 nm resolution. Specifically, demonstrate bandgap tunable interlayer interconversion between interlayer-trions -excitons, through combinational tip-induced engineering GPa-scale pressure plasmonic hot electron injection, simultaneous spectroscopic TEPL measurements. This unique nano-opto-electro-mechanical approach provides strategies developing versatile nano-excitonic/trionic devices heterobilayers.

Language: Английский

Citations

25
Coexisting Phases in Transition Metal Dichalcogenides: Overview, Synthesis, Applications, and Prospects DOI
Haiyang Liu, Yaping Wu, Zhiming Wu

et al.

ACS Nano, Journal Year: 2024, Volume and Issue: 18(4), P. 2708 - 2729

Published: Jan. 22, 2024

Over the past decade, significant advancements have been made in phase engineering of two-dimensional transition metal dichalcogenides (TMDCs), thereby allowing controlled synthesis various phases TMDCs and facile conversion between them. Recently, there has emerging interest TMDC coexisting phases, which contain multiple within one nanostructured TMDC. By taking advantage merits from component offer enhanced performance many aspects compared with single-phase TMDCs. Herein, this review article thoroughly expounds latest progress ongoing efforts on syntheses, properties, applications phases. The introduction section overviews main (2H, 3R, 1T, 1T′, 1Td), along advantages coexistence. subsequent focuses methods for TMDCs, particular attention to local patterning random formations. Furthermore, basis versatile properties their magnetism, valleytronics, field-effect transistors, memristors, catalysis are discussed. Lastly, a perspective is presented future development, challenges, potential opportunities This aims provide insights into 2D materials both scientific communities contribute further field.

Language: Английский

Citations

16
Strain Engineering of Twisted Bilayer Graphene: The Rise of Strain‐Twistronics DOI Creative Commons
Yuan Hou, Jingzhuo Zhou, Minmin Xue

et al.

Small, Journal Year: 2024, Volume and Issue: unknown

Published: April 15, 2024

Abstract The layer‐by‐layer stacked van der Waals structures (termed vdW hetero/homostructures) offer a new paradigm for materials design—their physical properties can be tuned by the vertical stacking sequence as well adding mechanical twist, stretch, and hydrostatic pressure to atomic structure. In particular, simple twisting of two layers graphene form uniform ordered Moiré superlattice, which effectively modulate electrons lead discovery unconventional superconductivity strong correlations. However, twist angle twisted bilayer (tBLG) is almost unchangeable once interlayer determined, while applying elastic strain provides an alternative way deeply regulate electronic structure controlling lattice spacing symmetry. this review, diverse experimental advances are introduced in straining tBLG in‐plane out‐of‐plane modes, followed characterizations calculations toward quantitatively tuning strain‐engineered structures. It further discussed that structural relaxation strained superlattice its influence on Finally, conclusion entails prospects opportunities 2D materials, discussions existing challenges, outlook intriguing emerging field, namely “strain‐twistronics”.

Language: Английский

Citations

15
High-κ Wide-Gap Layered Dielectric for Two-Dimensional van der Waals Heterostructures DOI Creative Commons
Aljoscha Söll, Edoardo Lopriore, Asmund Ottesen

et al.

ACS Nano, Journal Year: 2024, Volume and Issue: 18(15), P. 10397 - 10406

Published: April 1, 2024

van der Waals heterostructures of two-dimensional materials have unveiled frontiers in condensed matter physics, unlocking unexplored possibilities electronic and photonic device applications. However, the investigation wide-gap, high-κ layered dielectrics for devices based on structures has been relatively limited. In this work, we demonstrate an easily reproducible synthesis method rare-earth oxyhalide LaOBr, exfoliate it as a 2D material with measured static dielectric constant 9 wide bandgap 5.3 eV. Furthermore, our research demonstrates that LaOBr can be used field-effect transistors high performance low interface defect concentrations. Additionally, proves to attractive choice electrical gating excitonic materials. Our work versatile realization functionality systems wide-gap environments.

Language: Английский

Citations

12
Large-Area Epitaxial Growth of Transition Metal Dichalcogenides DOI
Guodong Xue, Biao Qin, Chaojie Ma

et al.

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(17), P. 9785 - 9865

Published: Aug. 12, 2024

Over the past decade, research on atomically thin two-dimensional (2D) transition metal dichalcogenides (TMDs) has expanded rapidly due to their unique properties such as high carrier mobility, significant excitonic effects, and strong spin–orbit couplings. Considerable attention from both scientific industrial communities fully fueled exploration of TMDs toward practical applications. Proposed scenarios, ultrascaled transistors, on-chip photonics, flexible optoelectronics, efficient electrocatalysis, critically depend scalable production large-area TMD films. Correspondingly, substantial efforts have been devoted refining synthesizing methodology 2D TMDs, which brought field a stage that necessitates comprehensive summary. In this Review, we give systematic overview basic designs advancements in epitaxial growth TMDs. We first sketch out fundamental structures diverse properties. Subsequent discussion encompasses state-of-the-art wafer-scale designs, single-crystal strategies, techniques for structure modification postprocessing. Additionally, highlight future directions application-driven material fabrication persistent challenges, aiming inspire ongoing along revolution modern semiconductor industry.

Language: Английский

Citations

11
Valleytronics Meets Straintronics: Valley Fine Structure Engineering of 2D Transition Metal Dichalcogenides DOI

Shichao Yang,

Hanyan Long,

Wenwei Chen

et al.

Advanced Optical Materials, Journal Year: 2024, Volume and Issue: 12(14)

Published: March 6, 2024

Abstract 2D transition metal dichalcogenides (TMDs) have emerged as a novel class of semiconductors with promising applications in optoelectronics, owing to their rich and tunable valley fine structure, known valleytronics. Strain engineering TMDs presents opportunities tailor structures band alignment, which greatly expands the potential investigate intrinsic properties improve device performance, thus opening new field straintronics. In this review, recent advances strain‐engineered are summarized, focus on phenomena enabled by precision tuning physics. The underlying mechanisms connections delineated between strain‐induced modifications based intravalley, intervalley, interlayer alignment single heterostructure TMDs. These insights allow targeted strain control strategies be devised for optimizing optoelectronic characteristics. This review provides perspectives guidance future directions valley‐straintronics flexible optoelectronics using TMDs, highlighting substantial promise valley‐strain fundamental physics studies well practical applications.

Language: Английский

Citations

10
Ultrafast atomic-scale scanning tunnelling spectroscopy of a single vacancy in a monolayer crystal DOI Creative Commons
Carmen Roelcke, Lukas Z. Kastner, Maximilian Graml

et al.

Nature Photonics, Journal Year: 2024, Volume and Issue: 18(6), P. 595 - 602

Published: March 14, 2024

Abstract Defects in atomically thin semiconductors and their moiré heterostructures have emerged as a unique testbed for quantum science. Strong light–matter coupling, large spin–orbit interaction enhanced Coulomb correlations facilitate spin–photon interface future qubit operations efficient single-photon emitters. Yet, directly observing the relevant interplay of electronic structure single defect with other microscopic elementary excitations on intrinsic length, time energy scales remained long-held dream. Here we resolve space, how spin–orbit-split level an isolated selenium vacancy moiré-distorted WSe 2 monolayer evolves under controlled excitation lattice vibrations, using lightwave scanning tunnelling microscopy spectroscopy. By locally launching phonon oscillation taking ultrafast energy-resolved snapshots vacancy’s states faster than vibration period, measure impact electron–phonon coupling single-atom defect. The combination atomic spatial, sub-picosecond temporal millielectronvolt resolution marks disruptive development towards comprehensive understanding complex materials, where key interactions can now be disentangled, one by one.

Language: Английский

Citations

9
Spin polarization detection via chirality-induced tunnelling currents in indium selenide DOI Creative Commons
Gabriele Pasquale, Paulo E. Faria, Shun Feng

et al.

Nature Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 8, 2025

Chirality, a basic property of symmetry breaking, is crucial for fields such as biology and physics. Recent advances in the study chiral systems have stimulated interest discovery symmetry-breaking states that enable exotic phenomena spontaneous gyrotropic order superconductivity. Here we examine interaction between light chirality electron spins indium selenide effect magnetic field on emerging tunnelling photocurrents at Van Hove singularity. Although symmetric under linearly polarized excitation, non-symmetric signal emerges when excitation circularly polarized, making it possible to electrically detect light's chirality. Our shows negligible out-of-plane g-factor few-layer valence band edge, resulting an unbalanced Zeeman splitting hexagonal boron nitride spin bands. This finding allows us measure change energy barrier height with exceptional resolution (~15 μeV). Furthermore, confirm long-standing theoretical prediction spin-polarized hole accumulation flat increasing laser powers. Light interactions dependence photocurrent are studied selenide, exploiting its response

Language: Английский

Citations

1
Light‐Induced Hysteresis of Electronic Polarization in Anti‐Ferromagnet FePS3 DOI
Kyung Ik Sim, Byung Cheol Park, Tae Soo Kim

et al.

Advanced Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 8, 2025

Abstract Research on manipulating materials using light has garnered significant interest, yet examples of controlling electronic polarization in magnetic remain scarce. Here, the hysteresis anti‐ferromagnetic semiconductor FePS 3 is demonstrated via light. Below Néel temperature, linear dichroism (i.e., optical anisotropy) without structural symmetry breaking observed. Light‐induced net aligns along a ‐axis (zigzag direction) at 1.6 eV due to dipolar and b (armchair 2.0 combined effects octupolar polarizations, resulting from charge transfer armchair zigzag direction by Unexpected occurs polarization, contrast absence such eV. This attributed light‐induced phase involving within spin lattice. Here new mechanism suggested for generating light, with implications future device applications.

Language: Английский

Citations

1