Bright excitonic multiplexing mediated by dark exciton transition in two-dimensional TMDCs at room temperature

Katznelson, Shaul; Cohn, Bar; Sufrin, Shmuel; Amit, Tomer; Mukherjee, Subhrajit; Kleiner, Vladimir; Mohapatra, Pranab K.; Patsha, Avinash; Ismach, Ariel; Refaely-Abramson, Sivan; Hasman, Erez; Koren, Elad

doi:10.1039/d1mh01186c

Cited by 8 publications

(6 citation statements)

References 66 publications

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“…Similar PL variations were observed in MoS 2 -based field effect devices and in ferroelectric lithium niobate (LiNbO 3 )-based MoSe 2 heterostructures . In addition, a slight redshift of the A- exciton is observed at positive applied back gate potential and is attributed to the increase in negatively charged Trion concentration. − Finally, a significant enhancement of the intensity ratio of B- to A- excitonic emission ( I B / I A ) is observed for negative poling (see Figure S4b). The observed PL modulation of the A- and B- excitonic emission can be explained based on the different electronic band alignment of the MoS 2 –In 2 Se 3 heterostructure for upward- and downward-induced polarizations (Figure d).…”

Section: Results and Discussionsupporting

confidence: 64%

Edge-Based Two-Dimensional α-In₂Se₃–MoS₂ Ferroelectric Field Effect Device

Dutta

Mukherjee

Uzhansky

et al. 2023

ACS Appl. Mater. Interfaces

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Heterostructures based on two-dimensional materials offer the possibility to achieve synergistic functionalities, which otherwise remain secluded by their individual counterparts. Herein, ferroelectric polarization switching in α-In 2 Se 3 has been utilized to engineer multilevel nonvolatile conduction states in a partially overlapping α-In 2 Se 3 −MoS 2 -based ferroelectric semiconducting field effect device. In particular, we demonstrate how the intercoupled ferroelectric nature of α-In 2 Se 3 allows to nonvolatilely switch between n-i and n-i-n type junction configurations based on a novel edge state actuation mechanism, paving the way for subnanometric scale nonvolatile device miniaturization. Furthermore, the induced asymmetric polarization enables enhanced photogenerated carriers' separation, resulting in an extremely high photoresponse of ∼1275 A/W in the visible range and strong nonvolatile modulation of the bright A-and B-excitonic emission channels in the overlaying MoS 2 monolayer. Our results show significant potential to harness the switchable polarization in partially overlapping α-In 2 Se 3 −MoS 2 based FeFETs to engineer multimodal, nonvolatile nanoscale electronic and optoelectronic devices.

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Section: Results and Discussionsupporting

confidence: 64%

Edge-Based Two-Dimensional α-In₂Se₃–MoS₂ Ferroelectric Field Effect Device

Dutta

Mukherjee

Uzhansky

et al. 2023

ACS Appl. Mater. Interfaces

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“…Our calculations show that the selection rules still hold in the heterostructure and, more importantly, that the Q point folded bands are optically inactive. The exciton spreading in k-space is also shown (using the calculated values of the Gr/WS 2 case, discussed in section II with details in supplemental note IV [72]) and reveals that only a small region around the K point is relevant, in line with robust GW and Bethe-Salpeter equation (BSE) calculations in bare monolayers [91]. Therefore, we can investigate the signatures of the WS 2 /Gr hybridization by simply computing the g-factors of CB ± and VB ± directly at the K points of the heterostructure.…”

Section: Proximitized Valley Zeeman Physics In Ws 2 /Graphene Heteros...mentioning

confidence: 58%

Proximity-enhanced valley Zeeman splitting at the WS₂/graphene interface

et al. 2023

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The valley Zeeman physics of excitons in monolayer transition metal dichalcogenides provides valuable insight into the spin and orbital degrees of freedom inherent to these materials. Being atomically-thin materials, these degrees of freedom can be influenced by the presence of adjacent layers, due to proximity interactions that arise from wave function overlap across the 2D interface. Here, we report 60 T magnetoreflection spectroscopy of the A- and B- excitons in monolayer WS$_2$, systematically encapsulated in monolayer graphene. While the observed variations of the valley Zeeman effect for the A- exciton are qualitatively in accord with expectations from the bandgap reduction and modification of the exciton binding energy due to the graphene-induced dielectric screening, the valley Zeeman effect for the B- exciton behaves markedly different. We investigate prototypical WS$_2$/graphene stacks employing first-principles calculations and find that the lower conduction band of WS$_2$ at the $K/K'$ valleys (the $CB^-$ band) is strongly influenced by the graphene layer on the orbital level. Specifically, our detailed microscopic analysis reveals that the conduction band at the $Q$ point of WS$_2$ mediates the coupling between $CB^-$ and graphene due to resonant energy conditions and strong coupling to the Dirac cone. This leads to variations in the valley Zeeman physics of the B- exciton, consistent with the experimental observations. Our results therefore expand the consequences of proximity effects in multilayer semiconductor stacks, showing that wave function hybridization can be a multi-step energetically resonant process, with different bands mediating the interlayer interactions. Such effects can be further exploited to resonantly engineer the spin-valley degrees of freedom in van der Waals and moiré heterostructures.

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“…[7][8][9] Furthermore, TMDCs exhibit exotic physics such as unconventional quantum Hall effect and quantum transport phenomena, [10] valley degrees of freedom, [11,12] and complex exciton physics . [3,[12][13][14][15][16] The doping techniques for the 3D bulk silicon, established over the past seven decades, [17] allows for the transition from intrinsic-to-extrinsic semiconductor nature, which is necessary for modern day technologies. Before TMDCs are ready to substitute silicon in electronic applications, suitable doping techniques for 2D materials must be found.…”

Section: Introductionmentioning

confidence: 99%

“…[ 7–9 ] Furthermore, TMDCs exhibit exotic physics such as unconventional quantum Hall effect and quantum transport phenomena, [ 10 ] valley degrees of freedom, [ 11,12 ] and complex exciton physics . [ 3,12–16 ]…”

Section: Introductionmentioning

confidence: 99%

Local Manipulation of the Energy Levels of 2D TMDCs on the Microscale Level via Microprinted Self‐Assembled Monolayers

Grützmacher

Heyl

Nardi

et al. 2023

Adv Materials Inter

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Abstract2D transition metal dichalcogenides (TMDCs) are atomically‐thick semiconductors with great potential for next‐generation optoelectronic applications, such as transistors and sensors. Their large surface‐to‐volume ratio makes them energy‐efficient but also extremely sensitive to the physical‐chemical surroundings. The latter must be carefully considered when predicting the electronic behavior, such as their energy level alignment, which ultimately affects the charge carrier injection and transport in devices. Here, local doping is demonstrated and thus adjusting the opto‐electronic properties of monolayer TMDCs (WSe2 and MoS2) by chemically engineering the surface of the supporting substrate. This is achieved by decorating the substrate by microcontact printing with patterns of two different self‐assembled monolayers (SAMs). The SAMs posses distinct molecular dipoles and dielectric constants, significantly influencing the TMDCs electronic and optical properties. By analyzing (on various substrtates), it is confirmed that these effects arise solely from the interaction between SAMs and TMDCs. Understanding the diverse dielectric environments experienced by TMDCs allows for a correlation between electronic and optical behaviours. The changes primarily involve alteration in the electronic band gap width, which can be calculated using the Schottky‐Mott rule, incorporating the dielectric screening of the TMDCs surroundings. This knowledge enables accurate prediction of the (opto‐)electronic behavior of monolayer TMDCs for advanced device design.

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Bright excitonic multiplexing mediated by dark exciton transition in two-dimensional TMDCs at room temperature

Abstract: 2D- semiconductors with strong light-matter interaction are attractive materials for integrated and tunable optical devices. Here, we demonstrate room-temperature wavelength multiplexing of the two-primary bright excitonic channels (Ab-, Bb-) in...

Cited by 8 publications

References 66 publications

Edge-Based Two-Dimensional α-In₂Se₃–MoS₂ Ferroelectric Field Effect Device

Edge-Based Two-Dimensional α-In₂Se₃–MoS₂ Ferroelectric Field Effect Device

Proximity-enhanced valley Zeeman splitting at the WS₂/graphene interface

Local Manipulation of the Energy Levels of 2D TMDCs on the Microscale Level via Microprinted Self‐Assembled Monolayers

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Bright excitonic multiplexing mediated by dark exciton transition in two-dimensional TMDCs at room temperature

Abstract: 2D- semiconductors with strong light-matter interaction are attractive materials for integrated and tunable optical devices. Here, we demonstrate room-temperature wavelength multiplexing of the two-primary bright excitonic channels (Ab-, Bb-) in...

Cited by 8 publications

References 66 publications

Edge-Based Two-Dimensional α-In2Se3–MoS2 Ferroelectric Field Effect Device

Edge-Based Two-Dimensional α-In2Se3–MoS2 Ferroelectric Field Effect Device

Proximity-enhanced valley Zeeman splitting at the WS2/graphene interface

Local Manipulation of the Energy Levels of 2D TMDCs on the Microscale Level via Microprinted Self‐Assembled Monolayers

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Product

Resources

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Edge-Based Two-Dimensional α-In₂Se₃–MoS₂ Ferroelectric Field Effect Device

Edge-Based Two-Dimensional α-In₂Se₃–MoS₂ Ferroelectric Field Effect Device

Proximity-enhanced valley Zeeman splitting at the WS₂/graphene interface