Related papers: Dimensional control of the band-gap crossover in l…
We performed high-throughput density functional theory calculations of optical matrix elements between band edges across a diverse set of non-magnetic two-dimensional monolayers with direct band gaps. Materials were ranked as potential…
In atomically thin transition metal dichalcogenide semiconductors, there is a crossover from indirect to direct bandgap as the thickness drops to one monolayer, which comes with a fast increase of the photoluminescence signal. Here, we show…
To explore new constituents in two-dimensional materials and to combine their best in van der Waals heterostructures, are in great demand as being unique platform to discover new physical phenomena and to design novel functionalities in…
Atomically thin films of III-VI post-transition metal chalcogenides (InSe and GaSe) form an interesting class of two-dimensional semiconductor that feature strong variations of their band gap as a function of the number of layers in the…
The band structures of bulk transition metal dichalcogenides ReS2 and ReSe2 are presented, showing the complicated nature of the interband transitions in these materials, with several close-lying band gaps. Three-dimensional plots of…
In light of the rise of transition metal dichalcogenides as 2D semiconductors for device applications, band engineering becomes very important from an application point of view. In many of these materials, such as the canonical example of…
Two-dimensional transition-metal dichalcogendes $MX_2$ (es. MoS$_2$, WS$_2$, MoSe$_2$, \ldots) are among the most promising materials for bandgap engineering. Widely studied in these compounds, by means of ab-initio techniques, is the…
Quantum systems in confined geometries are host to novel physical phenomena. Examples include quantum Hall systems in semiconductors and Dirac electrons in graphene. Interest in such systems has also been intensified by the recent discovery…
The electronic band structure of atomically thin semiconductors can be tuned by the application of a perpendicular electric field. The principle was demonstrated experimentally shortly after the discovery of graphene by opening a finite…
It has been recently claimed that bulk crystals of transition metal dichalcogenide (TMD) ReS$_2$ are direct band gap semiconductors, which would make this material an ideal candidate, among all TMDs, for the realization of efficient…
Beyond-diffraction-limit optical absorption spectroscopy provides profound information on the graded band structures of composition-spread and stacked two-dimensional materials, in which direct/indirect bandgap, interlayer coupling,…
Reliable and precise measurements of the relative energy of band edges in semiconductors are needed to determine band gaps and band offsets, as well as to establish the band diagram of devices and heterostructures. These measurements are…
We study the evolution of the band-gap structure in few-layer MoTe$_2$ crystals, by means of low-temperature micro-reflectance (MR) and temperature-dependent photoluminescence (PL) measurements. The analysis of the measurements indicate…
Methylammonium lead iodide perovskites are considered direct bandgap semiconductors. Here we show that in fact they present a weakly indirect bandgap 60 meV below the direct bandgap transition. This is a consequence of spin-orbit coupling…
Transition metal dichalcogenides (TMDs) are emerging as promising two-dimensional (2d) semiconductors for optoelectronic and flexible devices. However, a microscopic explanation of their photophysics -- of pivotal importance for the…
Understanding quasiparticle band structures of transition metal dichalcogenides (TMDs) is critical for technological advances of these materials for atomic layer electronics and photonics. Although theoretical calculations to date have…
Van der Waals heterostructures of 2D layered materials have gained much attention due to their flexible electronic properties, which make them promising candidates for energy, sensing, catalytic, and biomedical applications. Lead iodide…
Molybdenum disulfide (MoS$_2$), a layered van der Waals material, has attracted considerable attention as a promising alternative to graphene for applications in field-effect transistors and nanophotonic devices because of its sizable band…
We explore the direct to indirect band gap transitions in MX$_2$ (M= Mo/W, X= S/Se) transition metal dichalcogenides heterobilayers for different system compositions, strains, and twist angles based on first principles density functional…
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…