The emergence of rapidly expanding infectious diseases such as coronavirus (COVID-19) demands effective biosensors that can promptly detect and recognize the pathogens. Field-effect transistors based on semiconducting two-dimensional (2D) materials (2D-FETs) have been identified potential candidates for rapid label-free sensing applications. This is because any perturbation atomically thin 2D channels significantly impact their electronic transport properties. Here, we report use FET...

Strain-engineering in 2D transition metal dichalcogenide (TMD) semiconductors has garnered intense research interest tailoring the optical properties via strain-induced modifications of electronic bands TMDs, while its impact on exciton dynamics remains less understood. To address this, an extensive study transient absorption (TA) both W- and Mo-based single-crystalline monolayer TMDs grown by a recently developed laser-assisted evaporation method is performed. All spectral features...

Direct growth and patterning of atomically thin two-dimensional (2D) materials on various substrates are essential steps towards enabling their potential for use in the next generation electronic optoelectronic devices. The conventional gas-phase techniques, however, not compatible with direct processes. Similarly, condensed-phase methods, based metal oxide deposition chalcogenization processes, require lengthy processing times high temperatures. Here, a novel self-limiting laser...

This work reports the interfacial thermal conductance (G) and radiative recombination efficiency (β), also known as photoluminescence quantum yield (PL QY), of monolayer WSe2 flakes supported by fused silica substrates via energy-transport state-resolved Raman (ET-Raman). is first to consider effect electron-hole on transport characteristics single-layer transition-metal dichalcogenides (TMDs). ET-Raman uses a continuous-wave laser for steady-state heating well nanosecond picosecond lasers...

Excitons in two-dimensional transition metal dichalcogenide monolayers (2D-TMDs) are of essential importance due to their key involvement 2D-TMD-based applications. For instance, exciton dissociation and radiative recombination indispensible processes photovoltaic light-emitting devices, respectively. These two depend drastically on the photogeneration efficiency lifetime excitons. Here, we incorporate femtosecond pump-probe spectroscopy investigate ultrafast dynamics formation decay a...

Interest in layered two-dimensional (2D) materials has been escalating rapidly over the past few decades due to their promising optoelectronic and photonic properties emerging from atomically thin 2D structural confinements. When these are further confined lateral dimensions toward zero-dimensional (0D) structures, nanoparticles quantum dots with new can be formed. Here, we report a nonequilibrium gas-phase synthesis method for stoichiometric formation of gallium selenide (GaSe) ensembles...

Two-dimensional transition metal dichalcogenides (2D-TMDs) hold a great potential to platform future flexible optoelectronics. The beating hearts of these materials are their excitons known as XA and XB, which arise from transitions between spin-orbit split (SOS) levels in the conduction valence bands at K-point. functionality 2D-TMD-based devices is determined by dynamics excitons. One most consequential channels exciton decay on device defect-assisted recombination (DAR). Here, we employ...

The stability and reliability of emerging two-dimensional (2D) quantum materials subjected to harsh environments, such as high-energy radiation, are high importance, particularly in the fields space, defense, energy applications. In this work, we explored effects gamma radiation on structural optical properties monolayer WSe2 WS2 crystals. Raman photoluminescence spectroscopies were employed study probe radiation-induced changes samples after exposure intense (from a 60Co source) high-vacuum...

Abstract This work explores the 2D interfacial energy transport between monolayer WSe 2 and SiO while considering thermal nonequilibrium optical acoustic phonons caused by photoexcitation. Recent modeling experimental have shown substantial temperature differences (Δ T OA ) in various nanostructures upon laser irradiation. Generally, characterizations of resistance ( R ′′ tc at nanoscale are difficult depend on Raman‐probed measurements, which only reveal phonon information. Here it is that...

Tuning the structural and electronic properties of atomically thin two-dimensional (2D) materials via defect vacancy engineering is key to enabling their potential use in various applications, including electronics, energy, sensing devices. Vacancies are, for instance, becoming highly promising enhanced interaction gases biomolecules with 2D energy applications. However, deterministic generation desirable vacancies tunable concentrations remains a challenge due limitations current growth...

Understanding and controlling the growth evolution of atomically thin monolayer two-dimensional (2D) materials such as transition metal dichalcogenides (TMDCs) are vital for next-generation 2D electronics optoelectronic devices. However, their kinetics not fully observed or well understood due to bottlenecks associated with existing synthesis methods. This study demonstrates time-resolved ultrafast by a laser-based approach that enables rapid initiation termination vaporization process...

Recently, two-dimensional (2D) quantum materials and particularly transition metal dichalcogenides have emerged as an exciting class of atomically thin that possess extraordinary optoelectronic photonic properties. The strong light interactions with these not only govern their fascinating behavior but can also be used versatile synthesis processing tools to precisely tailor structures This review highlights the recent progress in laser-based approaches for 2D are often challenging via...

The interest in the wafer-scale growth of two-dimensional (2D) materials, including transition metal dichalcogenides (TMDCs), has been rising for transitioning from lab-scale devices to commercial-scale systems. Among various synthesis techniques, physical vapor deposition, such as pulsed laser deposition (PLD), shown promise 2D materials. However, due high volatility chalcogen atoms (e.g., S and Se), films deposited by PLD usually suffer a lack stoichiometry deficiency. To mitigate this...

We report experimental evidence of coherent interference between a weak probe and stronger coupling linearly polarized TEM00 cw-laser beams same wavelength on the vibratory dipoles crown glass surface.

Using recently developed laser-assisted synthesis technique (LAST), we demonstrate, for the first time, transient absorption (TA) exciton dynamics of W- and Mo-families TMDs that have strong excitation fluence dependence reach extremely long, several nanosecond lifetimes at highest fluences. To put this in context, all previous observations shown tens picosecond high powers (due to Auger recombination). a variety experimental approaches (excitation wavelength temperature dependent...

In this study, we demonstrate the potential manufacturing method and application of 2D WSe2-based field-effect transistors (2D-FETs) as a promising biosensor for selective rapid detection pathogen such SARS-CoV-2 in vitro. The sensors are manufactured by first synthesizing material on Si/SiO2 substrates, followed photolithography processes to form FET devices. Then, surface WSe2 has been functionalized with specific antibody selectively detect spike protein. TMDC-based 2D-FETs can...

Controlled and time-resolved growth of atomically thin monolayer transition-metal dichalcogenides (TMDCs) has long been demanded in the emerging field two-dimensional (2D) materials. However, due to complex precursor vaporization, mixing, chemistry as well random nucleation ultra-long times common synthesis techniques such CVD, understandings kinetics crystal evolution elusive. To address these challenges, here we introduce laser-assisted technique (LAST), where a continuous wave CO2 laser...

Two-dimensional (2D) materials such as transition metal dichalcogenides (TMDCs) have recently emerged an exciting class of quantum that can enable technological advancement in various fields, including electronics, optoelectronics, and photonics. Therefore, there is a significant demand for high-quality crystal growth wafer-scale integration methods to their properties from lab fab. Here, I will discuss some the laser-based synthesis techniques we developed control both single-crystalline 2D...