We report for the first time, fabrication of novel two-dimensional (2D) p-WS2/n-Si vertical heterostructures with superior junction and photoresponse characteristics. Few layer WS2 has been synthesized by a lithium-ion intercalation technique in hexane coated on Si substrates realization CMOS compatible devices. Atomic force microscopy Raman spectroscopy have used to confirm 2D nature layers. Sharp band-edge absorption emission peaks indicated formation mono-to-few-layers thick direct band...

Enhanced light–matter interactions by integrating plasmonic Au nanostructures as a light harvester on two-dimensional (2D) MoS2 carrier sink layers are reported, leading to broadband optical absorption and significantly enhanced Raman scattering intensity. The calculations of electronic band structure using density functional theory analysis simulations elucidate the metal induced doping in enhancement electromagnetic field through localized surface plasmon resonance at Au/MoS2 interface...

Chemical doping and plasmonic enhanced photoresponsivity of two dimensional (2D) n-WS2/p-Si heterojunctions are demonstrated for the first time. Novel PVP coated Ag0 intercalation induced synthesis has led to formation impurity-free, chemically doped few-layer n-WS2 with reversed conductivity following Maxwell-Wagner-Sillars interfacial effect. The resultant composite film exhibits excellent stability tunable absorption due silver nanoparticles different sizes. A sharp band-edge hybrid...

Strong light-matter interactions in layered transition metal dichalcogenides (TMDs) open up vivid possibilities for novel exciton-based devices. The optical properties of TMDs are dominated mostly by the tightly bound excitons and more complex quasiparticles, biexcitons. Instead physically exfoliated monolayers, solvent-mediated chemical exfoliation these 2D crystals is a cost-effective, large-scale production method suitable real device applications. We explore ultrafast excitonic processes...

Tunable electroluminescence properties of size-controlled Si nanocrystals embedded in silicon rich oxide films are demonstrated at room temperature, using an active light emitting layer the metal semiconductor device structure. Plasma enhanced chemical vapor deposited Si-rich were annealed elevated temperatures to form varying diameters. A typical redshift photoluminescence peak is observed with increasing annealing confirming formation quantum confined nanocrystals. The carrier transport...

Excitonic resonance and binding energies can be altered by controlling the environmental screening of attractive Coulomb potential. Although this response is often assumed to static, time evolution excitonic quasiparticles manifests a frequency dependence in its efficacy. In paper, we investigate ground (1s) first excited exciton state (2s) multilayered transition metal dichalcogenide $({\mathrm{MoS}}_{2})$ upon ultrafast photoexcitation. We explore dynamic effects on latter show relevant at...

Quantum emitters in two-dimensional layered hexagonal boron nitride are quickly emerging as a highly promising platform for next-generation quantum technologies. However, the precise identification and control of defects key parameters to achieve next step their development. We conducted comprehensive study by analyzing over 10,000 photoluminescence emission lines from liquid exfoliated hBN nanoflake samples, revealing 11 narrow sets defect families within 1.6 2.2 eV energy range. This...

Understanding the charge transfer dynamics at interface of metals and semiconductors has received much attention in efficient plasmonic induced photonic devices. Here, we present ultrafast Au–ZnO nanocomposite systems by exciting them interband intraband levels Au with pump energies higher (2.48 eV) lower (1.96 than threshold energy for transition (2.4 eV), using femtosecond time-resolved pump-probe technique. The spectral responses both excitations exhibit different behaviors, these...

Abstract Strong light–matter interactions between resonantly coupled metal plasmons and spin–orbit‐coupled bright excitons from 2D transition dichalcogenides (TMDs) can produce discrete exciton–plasmon polaritons (plexcitons). A few efforts have been made to perceive the spin‐induced exciton‐polaritons in nanocavities at cryogenic conditions, however, successful realization of plexcitons time domain is still lacking. Here, both are identified discretely room temperature their ultrafast...

The plasmon-enhanced photoresponse properties of a Ag nanoparticle decorated Bi2Se3 nanosheet (AGBS)/p-Si heterojunction device have been studied. nanoparticles, nanosheets, and AGBS nanocomposite are synthesized chemically. Microscopic investigations, ultimately the nanocomposite, reveal that nanosheets thickness ∼20 nm lateral dimension ∼1 μm with nanoparticles sizes 20-40 in nanocomposite. x-ray diffraction pattern shows apart from being metallic state, is also form compounds Bi, Se,...

Ultrafast observation of multiple asymmetric Fano line shapes in energetically overlapped single continuum and discrete states is great theoretical interest different domains physics, though their real-time experimental demonstrations are yet to be achieved. Here, we present an on time-domain response the double asymmetries a metal--two-dimensional semiconductor hybrid prototype at room temperature. The ultrafast interactions two spin-resolved excitons ${\mathrm{MoS}}_{2}$ metal...

Mott transition has been realized in atomically thin monolayers (MLs) of two-dimensional (2D) semiconductors ($\mathrm{W}{\mathrm{S}}_{2}$) via optically excited carriers above a critical carrier density through many-body interactions. The nonlinear optical occurs when electron hole pairs the ML $\mathrm{W}{\mathrm{S}}_{2}$ continuum heavily interact with each other followed by transformation into collective electron-hole-plasma phase, losing their identity as individual quasiparticles. This...

Group-VII transition metal dichalcogenides like ReS₂ holds novel in-plane anisotropic excitons, owing to their reduced lattice symmetry. Despite potential, the coherent dynamics of these excitons remain unexplored yet. To address properties, here, we perform polarization sensitive, ultrafast non-linear optical measurements on ReS₂. By implementing four-wave mixing spectroscopy along with spectral heterodyning detection at microscopic limit, measure coherence and...

Quantum emitters in two-dimensional layered hexagonal boron nitride are quickly emerging as a highly promising platform for next-generation quantum technologies. However, precise identification and control of defects key parameters to achieve the next step their development. We conducted comprehensive study by analyzing over 10,000 photoluminescence emission lines, revealing 11 distinct defect families within 1.6 2.2 eV energy range, challenging hypotheses random distribution. These findings...

The discovery of in-plane anisotropic excitons in two-dimensional layered semiconductors enables state-of-the-art nanophotonic applications. A fundamental yet unknown parameter these quasiparticles is the coherence time (T_2 ), which governs quantum dephasing timescale, over coherent superposition can be maintained and manipulated. Here, we report direct measurement T_2 within sub-picosecond range, along with multiple population decay timescales (T_1 ) at resonance for pristine rhenium...

We study transient absorption response of few-layered MoS₂ nano-flakes in dispersion, mainly focusing on its high energy exciton (commonly known as C exciton). use a simple sono-chemical exfoliation technique to obtain confined nano-crystals average diameter 2 nm, inter-dispersed the flakes and effect quantum confinement this layered semiconductor. emphasize interplay between bleaching excited state upon blue-detuned pumping. The relaxation times for are found radiative process is...

Here, we develop a novel chemical exfoliation method for synthesis of few layers WS2, decorated with core-shell structured polymer coated silver nanoparticles development stable 2D-plasmonic composite as next day photonic device paradigms.

Quantum emitters in two-dimensional layered hexagonal boron nitride are quickly emerging as a highly promising platform for next-generation quantum technologies. However, precise identification and control of defects key parameters to achieve the next step their development. We conducted comprehensive study by analyzing over 10,000 photoluminescence emission lines, revealing 11 distinct defect families within 1.6 2.2 eV energy range. This challenges hypotheses random distribution. also...

Strong light-matter interactions between resonantly coupled metal plasmons and spin decoupled bright excitons from two dimensional (2D) transition dichalcogenides (TMDs) can produce discrete spin-resolved exciton-plasmon polariton (plexciton). A few efforts have been made to perceive the induced exciton-polaritons in nanocavities at cryogenic conditions, however, successful realization of plexciton time-domain is still lacking. Here, we are able identify both plexcitons discretely room...

Mott transition has been realized in atomically thin monolayer (ML) of two dimensional semiconductors (WS$_2$) via optically excited carriers above a critical carrier density through many body interactions. The nonlinear optical occurs when electron hole pairs ML WS2 continuum heavily interact with each other followed by transformation into collective plasma phase (EHP), losing their identity as individual quasiparticles. This is manifested the alluring red-shift-blue-shift crossover (RBC)...