Phys.org June 28, 2022 Researchers in China presented the observation of the IXs in trilayer type-II staggered band alignment of MoS2/MoSe2/WSe2 van der Waals (vdW) HSs by photoluminescence (PL) spectroscopy. The central energy of IX is 1.33 eV, and the energy difference between the extracted double peaks is 23 meV. They confirmed the origin of IX through PL properties and calculations by the density functional theory and studied the dependence of the IX emission peak on laser power and temperature. The polarization-resolved PL spectra of HS were also investigated, and the maximum polarizability of the emission peak of WSe2 reached […]
Tag Archives: Excitons
‘Crazy’ light emitters: Physicists see an unusual quantum phenomenon
Nanowerk December 14, 2021 An international team of researchers (Germany, USA – Lawrence Berkeley National Laboratory, Sweden, Japan) has visualized the rapid movement of excitons in atomically thin semiconductors using highly sensitive optical microscopy. First, they applied a short laser pulse to the material and then used an ultrafast detector to observe when and where the light was reemitted. They found the excitons to move in opposite directions at the same time. The only possible explanation was that the excitons would occasionally move through closed loops in opposite directions at the same time. Such behavior was in fact known from […]
Towards straintronics: Guiding excitons in 2D materials
Science Daily October 30, 2021 Strain engineering is a powerful tool in designing artificial platforms for high-temperature excitonic quantum devices. An international team of researchers (USA – City College of New York, Germany, Japan) has created excitonic wires, essentially one-dimensional channels for excitons in what is otherwise a two-dimensional semiconductor by depositing the atomically thin 2D crystal on top of a microscopically small wire they created a small, elongated dent in the two-dimensional material, slightly pulling apart the atoms in the two-dimensional crystal and inducing strain in the material. For excitons, this dent is much like a pipe and once trapped […]
Scientists use photons as threads to weave novel forms of matter
EurekAlert August 17, 2020 An international team of researchers (UK, France, Italy) has spectroscopically observed bound electrons and holes, leading to the creation of an intraband bound exciton. The discrete resonance appears below the ionization threshold only when the coupling between light and matter is increased above a critical value. The result demonstrates that two charged particles can be bound by the exchange of transverse photons. Light–matter coupling can thus be used as a tool in quantum material engineering, tuning electronic properties of semiconductor heterostructures beyond those permitted by mere crystal structures, with direct applications to mid-infrared optoelectronics…read more. TECHNICAL […]