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Related papers: Exciton dynamics in WSe2 bilayers

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Excitons, Coulomb-bound electron-hole pairs, are the fundamental excitations governing the optoelectronic properties of semiconductors. While optical signatures of excitons have been studied extensively, experimental access to the excitonic…

Low-temperature photoluminescence (PL) of hBN-encapsulated monolayer tungsten diselenide (WSe$_2$) shows a multitude of sharp emission peaks below the bright exciton. Some of them have been recently identified as phonon sidebands of…

Observations of polariton condensation in semiconductor microcavities suggest that polaritons can be exploited as a novel type of laser with low input-power requirements. The low-excitation regime is approximately equivalent to thermal…

Mesoscale and Nanoscale Physics · Physics 2013-07-16 Tomoyuki Horikiri , Yasuhiro Matsuo , Yutaka Shikano , Andreas Loeffler , Sven Hoefling , Alfred Forchel , Yoshihisa Yamamoto

The carrier spin dynamics in ZnO is investigated by time-resolved optical orientation experiments. We evidence a clear circular polarization of the donor-bound exciton luminescence in both ZnO epilayer and non-intentionally doped bulk ZnO.…

Other Condensed Matter · Physics 2008-04-16 D. Lagarde , A. Balocchi , P. Renucci , H. Carrère , F. Zhao , T. Amand , X. Marie , Z. X. Mei , X. L. Du , Q. K. Xue

The photoluminescence (PL) and absorption experiments have been performed in GaSe slab with incident light polarized perpendicular to c-axis of sample at 10K. An obvious energy difference of about 34meV between exciton absorption peak and…

Mesoscale and Nanoscale Physics · Physics 2016-03-08 Chengrong Wei , Xi Chen , Dian Li , Huimin Su , Jun-Feng Dai

A recent single quantum wire is of sufficient quality to reveal new details of the photoluminescence (PL) evolution with increasing electron--hole (e--h) pair density. At a pair density of 3.6 $\times$ 10$^{3}$ cm$^{-1}$, the PL is…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Masahiro Yoshita , Yuhei Hayamizu , Hidefumi Akiyama , Loren N. Pfeiffer , Ken W. West , Kenichi Asano , Tetsuo Ogawa

The picosecond dynamics of excitons in colloidal CdSe nanorods are directly measured via their 1s to 2p-like internal transitions by ultra-broadband terahertz spectroscopy. Broadened absorption peaks from both the longitudinal and…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 David G. Cooke , Peter Uhd Jepsen , Jun Yan Lek , Yeng Ming Lam , Fredrik Sy , Marc M. Dignam

We study the photoluminescence (PL) of a two-dimensional liquid of oriented dipolar excitons in In_{x}Ga_{1-x}As coupled double quantum wells confined to a microtrap. Generating excitons outside the trap and transferring them at lattice…

Mesoscale and Nanoscale Physics · Physics 2012-04-17 G. J. Schinner , J. Repp , E. Schubert , A. K. Rai , D. Reuter , A. D. Wieck , A. O. Govorov , A. W. Holleitner , J. P. Kotthaus

Developments in optoelectronics and spin-optronics based on transition metal dichalcogenide monolayers (MLs) need materials with efficient optical emission and well-defined transition energies. In as-exfoliated MoS2 MLs the…

Single-layer WS$_2$ is a direct-gap semiconductor showing strong excitonic photoluminescence features in the visible spectral range. Here, we present temperature-dependent photoluminescence measurements on mechanically exfoliated…

Mesoscale and Nanoscale Physics · Physics 2015-09-08 Gerd Plechinger , Philipp Nagler , Julia Kraus , Nicola Paradiso , Christoph Strunk , Christian Schüller , Tobias Korn

Optical interband transitions in monolayer transition metal dichalcogenides such as WSe2 and MoS2 are governed by chiral selection rules. This allows efficient optical initialization of an electron in a specific K-valley in momentum space.…

Mesoscale and Nanoscale Physics · Physics 2014-09-09 G. Wang , L. Bouet , D. Lagarde , M. Vidal , A. Balocchi , T. Amand , X. Marie , B. Urbaszek

We study dynamics of incoherent exciton formation under interband photoexcitation in Cu$_2$O using time-and angle-resolved photoemission spectroscopy at 90 K. Hot electrons injected by allowed optical transitions with 3.40-eV photons show…

Mesoscale and Nanoscale Physics · Physics 2019-10-23 H. Tanimura , K. Tanimura , P. H. M. van Loosdrecht

We present a theoretical model that allows us to describe the dynamics of exciton polaritons in the strong-coupling regime in a monolayer WS2 based semiconductor microcavity. Numerical simulations using Boltzmann equations give an overall…

Mesoscale and Nanoscale Physics · Physics 2018-06-12 Mohamed Herira , Hela Boustanji , Sihem Jaziri

We experimentally investigated for the first time the lowest four band structure of Cd Se nanoplatelets at the r point of Brillouin zone [heavy-hole (hh), light-hole (lh) and two spin-orbital bands] and its modification due to the changing…

We report on the far-field photoluminescence intensity distribution of interlayer excitons in MoSe$_{2}$-WSe$_{2}$ heterostacks as measured by back focal plane imaging in the temperature range between 1.7 K and 20 K. By comparing the data…

We experimentally demonstrate hot exciton transport in h-BN encapsulated WSe2 monolayers via spatially and temporally resolved photoluminescence measurements at room temperature. We show that the nonlinear evolution of the mean squared…

Mesoscale and Nanoscale Physics · Physics 2019-12-11 Darwin F. Cordovilla Leon , Zidong Li , Sung Woon Jang , Parag B. Deotare

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

Collective electronic excitations "excitons" in planar optical lattices exhibit strong modifications of the radiative damping rate and directional emission pattern as compared to a single excited atom. Excitons for long wave numbers and…

Quantum Physics · Physics 2011-06-27 Hashem Zoubi , Helmut Ritsch

Second-order time correlation measurements with a temporal resolution better than 3 ps were performed on a CdTe microcavity where spontaneous Bose-Einstein condensation is observed. After the laser pulse, the nonresonantly excited thermal…

Two-dimensional (2D) van der Waals (vdW) heterostructures (HSs) provide a versatile platform for tailoring electronic, optical, and magnetic properties via proximity effects at their interfaces. In this work, we explore the optical response…