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Related papers: Hot exciton transport in WSe2 monolayers

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A three-step process was developed for growing high-quality, optically uniform WSe2 monolayers by molecular beam epitaxy (MBE) with advantage of using hexagonal boron nitride (hBN). The process was optimized to maximize the efficiency of…

Bose-Fermi mixtures naturally appear in various physical systems. In semiconductor heterostructures, such mixtures can be realized, with bosons as excitons and fermions as dopant charges. However, the complexity of these hybrid systems…

Unconventional emissions from exciton and trion in monolayer WS2 are studied by photoexcitation. Excited by 532nm laser beam, the carrier species in the monolayer WS2 are affected by the excess electrons escaping from photoionization of…

Mesoscale and Nanoscale Physics · Physics 2016-08-08 Ke Wei , Yu Liu , Hang Yang , Xiangai Cheng , Tian Jiang

We reveal the higher energetic luminescence part of interlayer exciton ensembles in MoSe$_2$/WSe$_2$ heterostructures upon excitation by an optical Laguerre-Gaussian mode. The excitation is achieved with the help of a spatial light…

Monolayer semiconductors are atomically thin quantum wells with strong confinement of electrons in two-dimensional (2D) plane. Here, we experimentally study the out-of-plane polarizability of excitons in hBN-encapsulated monolayer WSe$_{2}$…

Mesoscale and Nanoscale Physics · Physics 2019-02-19 Ivan A. Verzhbitskiy , Daniele Vella , Kenji Watanabe , Takashi Taniguchi , Goki Eda

Two-dimensional semiconductors exhibit pronounced many-body effects and intense optical responses due to strong coulombic interactions. Consequently, subtle differences in photoexcitation conditions can strongly influence how the material…

Monolayers of transition metal dichalcogenide materials emerged as a new material class to study excitonic effects in solid state, since they benefit from enormous coulomb correlations between electrons and holes. Especially in WSe2, sharp…

We study photoluminescence (PL) spectra and exciton dynamics of MoS$_2$ monolayer (ML) grown by the chemical vapor deposition technique. In addition to the usual direct A-exciton line we observe a low-energy line of bound excitons…

Mesoscale and Nanoscale Physics · Physics 2021-09-14 M. A. Akmaev , M. M. Glazov , M. V. Kochiev , P. V. Vinokurov , S. A. Smagulova , V. V. Belykh

Chemical vapor deposition (CVD) allows lateral edge epitaxy of transition metal dichalcogenide heterostructures with potential applications in optoelectronics. Critical for carrier and exciton transport is the quality of the two materials…

Strongly bound excitons confined in two-dimensional (2D) semiconductors are dipoles with a perfect in-plane orientation. In a vertical stack of semiconducting 2D crystals, such in-plane excitonic dipoles are expected to efficiently couple…

We study experimentally and theoretically the exciton-phonon interaction in MoSe2 monolayers encapsulated in hexagonal BN, which has an important impact on both optical absorption and emission processes. The exciton transition linewidth…

By implementing four-wave mixing (FWM) micro-spectroscopy we measure coherence and population dynamics of the exciton transitions in monolayers of MoSe$_2$. We reveal their dephasing times T$_2$ and radiative lifetime T$_1$ in a…

The optical properties of two-dimensional transition metal dichalcogenide monolayers such as MoS$_2$ or WSe$_2$ are dominated by excitons, Coulomb bound electron-hole pairs. Screening effects due the presence of hexagonal-BN surrounding…

Materials Science · Physics 2018-12-26 Iann C. Gerber , Xavier Marie

We investigate the excitonic dynamics in MoSe2 monolayer and bulk samples by femtosecond transient absorption microscopy. Excitons are resonantly injected by a 750-nm and 100-fs laser pulse, and are detected by a probe pulse tuned in the…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 Nardeep Kumar , Qiannan Cui , Frank Ceballos , Dawei He , Yongsheng Wang , Hui Zhao

In superlattices of twisted semiconductor monolayers, tunable moir\'e potentials emerge, trapping excitons into periodic arrays. In particular, spatially separated interlayer excitons are subject to a deep potential landscape and they…

Mesoscale and Nanoscale Physics · Physics 2023-06-02 Samuel Brem , Ermin Malic

A single monolayer of the layered semimetal WTe2 behaves as a two-dimensional topological insulator, with helical conducting edge modes surrounding a bulk state that becomes insulating at low temperatures. Here we present evidence that the…

The role of noise in the transport properties of quantum excitations is a topic of great importance in many fields, from organic semiconductors for technological applications to light-harvesting complexes in photosynthesis. In this paper we…

Quantum Physics · Physics 2016-11-22 Stefano Iubini , Octavi Boada , Yasser Omar , Francesco Piazza

Twisted transition metal dichalcogenides (TMDs) present an intriguing platform for exploring excitons and their transport properties. By introducing a twist angle, a moir\'e superlattice forms, providing a spatially dependent exciton energy…

Mesoscale and Nanoscale Physics · Physics 2024-01-17 Willy Knorr , Samuel Brem , Giuseppe Meneghini , Ermin Malic

Newly measured optical absorption and photoluminescence spectra reveal substantial frequency shifts of both exciton and trion peaks as monolayer MoS2 is cooled from 363 K to 4 K. First-principles simulations using the GW-Bethe-Salpeter…

Mesoscale and Nanoscale Physics · Physics 2014-05-22 Ryan Soklaski , Yufeng Liang , Changjian Zhang , Haining Wang , Farhan Rana , Li Yang

Two-dimensional (2D) semiconducting materials are promising building blocks for optoelectronic applications, many of which require efficient dissociation of excitons into free electrons and holes. However, the strongly bound excitons…