Related papers: Intervalley scattering in MoS$_2$ imaged by two-ph…
We have investigated the electronic excitations in bulk 2H-MoS2 using electron energy-loss spectroscopy. The electron energy-loss spectra in the {\Gamma}M and {\Gamma}K directions were measured for various momentum transfer values. The…
Photo-induced charge separation in transition metal dichalcogenide heterobilayers is being explored for moir\'e excitons, spin-valley polarization, and quantum phases of excitons/electrons. While different momentum spaces may be critically…
Despite the weak, van-der-Waals interlayer coupling, photoinduced charge transfer vertically across atomically thin interfaces can occur within surprisingly fast, sub-50fs timescales. Early theoretical understanding of the charge transfer…
Two-dimensional transition metal dichalcogenides (TMD) offer a unique platform for creating van-der-Waals heterojunctions with fascinating physical properties and promising applications in optoelectronics and valleytronics. Because of their…
We have investigated indirect excitons in bulk $2H$-MoS$_2$ using transmission electron energy-loss spectroscopy. The electron energy-loss spectra were measured for various momentum transfer values parallel to the $\Gamma$K and $\Gamma$M…
Our examination of the interplay of ultrafast charge dynamics and electron-phonon interaction in bilayer MoS2 provides a microscopic basis for understanding the features (two peaks) in the emission spectrum. We demonstrate that while the…
The anisotropy of the electronic transition is an important physical property not only determining the materials' optical property, but also revealing the underlying character of the electronic states involved. Here we used…
Charge transfer in type-II heterostructures plays important roles in determining device performance for photovoltaic and photocatalytic applications. However, current theoretical studies of charge transfer process don't consider the effects…
Transition metal dichalcogenides layered nano-crystals are emerging as promising candidates for next-generation optoelectronic and quantum devices. In such systems, the interaction between excitonic states and atomic vibrations is crucial…
We combine linear and non-linear optical spectroscopy at 4K with ab initio calculations to study the electronic bandstructure of MoSe2 monolayers. In 1-photon photoluminescence excitation (PLE) and reflectivity we measure a separation…
The influence of strong internal forces on photon-assisted scattering and on the displacement mechanism of magnetoconductivity oscillations in a two-dimensional (2D) electron gas is theoretically studied. The theory is applied to the highly…
We measure the second-harmonic (SH) response of MoS$_2$ in a broad fundamental photon energy range between 0.85 and 1.7 eV, and present a continuous SH spectrum capturing signatures of both the fundamental A and B excitons in addition to…
The junction of a scanning tunneling microscope (STM) operating in the tunneling regime was irradiated with femtosecond laser pulses. A photo-excited hot electron in the STM tip resonantly tunnels into an excited state of a single molecule…
For a molecule, the two-center interference and the molecular scattering phase of the electron are important for almost all the processes that may occur in a laser field. In this study, we investigate their effects in the transfer of linear…
The optical and electronic properties of 2D semiconductors are intrinsically linked via the strong interactions between optically excited bound species and free carriers. Here we use near-field scanning microwave microscopy (SMM) to image…
We use helicity-resolved ultrafast transient absorption spectroscopy to study spin-valley polarization dynamics in a vertically stacked MoSe$_{2}$/WSe$_{2}$ heterostructure. The experimental findings reveal details of interlayer charge…
The dynamics of excited electrons and holes in single layer (SL) MoS$_2$ have so far been difficult to disentangle from the excitons that dominate the optical response of this material. Here, we use time- and angle-resolved photoemission…
Energy transfer (ET) is a dipole-dipole interaction, mediated by the virtual photon. Traditionally, ET happens from the higher (donor) to lower bandgap (acceptor) material. However, in some rare instances, ET can happen from the…
In this study,we combined time-resolved terahertz spectroscopy along with transient absorption spectroscopy to revisit the interlayer non-equilibrium carrier dynamics in largely lateral size Gr/MoS2 heterostructure fabricated with chemical…
Among newly discovered two-dimensional (2D) materials, semiconducting ultrathin sheets of MoS2 show potential for nanoelectronics. However, the carrier mobility in MoS2 is limited by scattering from surface impurities and the substrate. To…