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Template growth of Au/Ag nanocomposites on phosphorene for sensitive SERS detection of pesticides
摘要： We report template growth and dense packing of noble metallic nanoparticles on few-layer phosphorene for sensitive SERS detection. Phosphorene obtained by electrochemical exfoliation serves as both the template and reductant in the fabrication of noble metallic nanoparticles which are dispersed on phosphorene without aggregation or pile-up. The BP/Ag/Au and BP/Au/Ag nanocomposites with a nanogap structure exhibit excellent SERS sensitivity and reproducibility with respect to Rhodamine 6G (R6G). The BP/Au/Ag nanocomposite is further utilized as the SERS substrate for the detection of two fungicides, thiabendazole and thiram, and detection limits of 10-7 and 10-8 M are achieved. Template growth of Au/Ag nanocomposites is demonstrated to be a green strategy for the fabrication of SERS substrates and has large potential in applications such as pesticide detection.
关键词： template growth,nanocomposites,phosphorene,SERS
更新于2025-11-21 11:01:37
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Linear and Nonlinear Optical Properties of Few-Layer Exfoliated SnSe Nanosheets
摘要： Monochalcogenides of group IV elements have been considered as phosphorene analogs due to their similar crystal and electronic structure. Here, few-layer SnSe nanosheets are synthesized by a sonication-assisted liquid phase exfoliation process and their linear and nonlinear optical properties are examined. The as-exfoliated few-layer (FL) SnSe demonstrates layer thickness from 2 to 10 nm and lateral size of 150 nm with high crystallinity. Optical measurement confirms the layer-number dependent bandgap, which is also corroborated by first-principle calculation. In addition, the FL SnSe shows a transition from saturable absorption to reverse saturable absorption with the increase of pumping power, and the nonlinear absorption is characterized by an ultrafast response time of picosecond scale. The nonlinear optical response in FL SnSe could be explained by defect-involved recombination of photogenerated carriers as well as the Auger scattering process, which is further enhanced by structural two-dimensionality.
关键词： nonlinear optics,phosphorene analogue,SnSe,liquid-phase exfoliation,2D semiconductors
更新于2025-09-23 15:23:52
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B-Doping-Enhanced Stability of Phosphorene/Graphene Heterostructures
摘要： Two-dimensional material heterostructures show large surface area and unusual electronic properties, being used in nanoelectronic devices, energy storage devices, and sensors. Doping can improve stability of the heterostructures. Structural and electronic properties of B–doped phosphorene/graphene heterostructures are studied using ?rst-principles calculations. B doping in phosphorene enhances the interlayer charge transfer from phosphorene to graphene. Importantly, B doping creates strong chemical bonding at the interface, which improves stability of phosphorene/graphene heterostructures. The band gap is opened up to 0.53 eV by B doping.
关键词： heterostructure,DFT calculations,graphene,phosphorene,chemical bonding
更新于2025-09-23 15:23:52
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Evaluating the Surface Chemistry of Black Phosphorus during Ambient Degradation
摘要： Black Phosphorus (BP) is emerging as a promising candidate for electronic, optical and energy storage applications, however its poor ambient stability remains a critical challenge. Evaluation of few-layer liquid exfoliated BP during ambient exposure using x-ray photoelectron spectroscopy (XPS) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) allows its surface chemistry to be investigated. Oxidation of liquid exfoliated few-layer BP initially occurs through non-bridging oxide species, which convert to bridging oxide species after ambient exposure. We demonstrate the instability of these bridging oxide species, which undergo hydrolysis to form volatile phosphorus oxides and evaporate from the BP surface. FTIR spectroscopy, scanning transmission electron microscopy and atomic force microscopy were used to confirm the formation of liquid oxides through a continuous oxidation cycle that results in the decomposition of BP. Furthermore, we show that the instability of few-layer BP originates from the formation of bridging oxide species.
关键词： Fourier transform infrared spectroscopy,Black phosphorus,phosphorene,x-ray photoelectron spectroscopy,2D materials,degradation,ambient stability,oxidation
更新于2025-09-23 15:23:52
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[IEEE 2018 18th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM) - Waterloo, ON (2018.8.19-2018.8.22)] 2018 18th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM) - Excitation of Hyperbolic Plasmons and Transition Radiation in Phosphorene by a Swift Electron
摘要： We analyze the energy loss channels for a fast electron traversing a monolayer phosphorene under oblique incidence taking the retardation effects into account.
关键词： transition radiation,electron energy loss,retardation effects,Phosphorene,hyperbolic plasmon polariton
更新于2025-09-23 15:23:52
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Strain-Engineered Ultrahigh Mobility in Phosphorene for Terahertz Transistors
摘要： Carrier mobility is a key parameter for the operation of electronic devices as it determines the ON state current and switching speed/frequency response of transistors. 2D phosphorene is considered as a potential candidate for field-effect transistors due to its high mobility. Here it is proposed to further enhance the carrier mobility of phosphorene and device performance via strain engineering. A systematic ab initio investigation on the anisotropic electronic structure of few-layer phosphorene reveals that the monolayer under 7.5–10% strain along zigzag direction shows an exceptional carrier mobility of ≈106 cm2 V?1 s?1, which is 10 times higher than the strain-free case. The simulated device performance shows that strain-engineered phosphorene–based field-effect transistors demonstrate a cut-off frequency of ≈1.14 THz with a gate length of 1.0 micron and 112 THz with a sub-10 nm gate length.
关键词： carrier mobility,density functional theory,phosphorene,transistors,strain-engineered electronics
更新于2025-09-23 15:22:29
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Difluorophosphorane - Flattened Phosphorene through Difluorination
摘要： We computationally showed that by difluorination of phosphorene we can make a new material difluorphosphorane (DFP) with perfectly planar honeycomb structure out of phosphorus atoms with fluorine atoms attached to every phosphorus atom from above and below. The structure is dynamically stable. It is a semiconductor with the direct band gap of 4.51 eV and 3.88 eV for the indirect band gap. We hope that with the passivation this new DFP material if made could find many applications in nanoelectronics.
关键词： difluorination,difluorophosphorane,nanoelectronics,phosphorene,semiconductor
更新于2025-09-23 15:21:21
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Synergistic Cascade Carrier Extraction via Dual Interfacial Positioning of Ambipolar Black Phosphorene for Higha??Efficiency Perovskite Solar Cells
摘要： 2D black phosphorene (BP) carries a stellar set of physical properties such as conveniently tunable bandgap and extremely high ambipolar carrier mobility for optoelectronic devices. Herein, the judicious design and positioning of BP with tailored thickness as dual-functional nanomaterials to concurrently enhance carrier extraction at both electron transport layer/perovskite and perovskite/hole transport layer interfaces for high-efficiency and stable perovskite solar cells is reported. The synergy of favorable band energy alignment and concerted cascade interfacial carrier extraction, rendered by concurrent positioning of BP, delivered a progressively enhanced power conversion efficiency of 19.83% from 16.95% (BP-free). Investigation into interfacial engineering further reveals enhanced light absorption and reduced trap density for improved photovoltaic performance with BP incorporation. This work demonstrates the appealing characteristic of rational implementation of BP as dual-functional transport material for a diversity of optoelectronic devices, including photodetectors, sensors, light-emitting diodes, etc.
关键词： ambipolar carrier mobility,cascade interfacial carrier extraction,black phosphorene,perovskite solar cells,band energy alignment
更新于2025-09-23 15:21:01
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Abnormal scaling of excitons in phosphorene quantum dots
摘要： Excitonic states of a many-electron system in phosphorene quantum dots (PQDs) are investigated theoretically by using a configuration interaction approach. For a triangular PQD in various dielectric environments, its exciton is found to obey two distinct scaling rules. When there is strong screening effect present in the nanodot, the exciton binding energy (?ex) is shown to be around ?150 meV as the long-range Coulomb interactions are totally suppressed and increases to about 100 meV when the effective dielectric constant (εr) decreases to 12.5. Over this range of εr, ?ex is found to be well fitted into a quadratic form of ε?1 r like the case of bulk three-dimensional semiconductors nor linearly with ε?1 r like the case previously reported for graphene nanostructures. When εr is reduced below 10.0, however, ?ex is shown to exhibit a perfect linear relation with ε?1 r, which behaves just like that of a two-dimensional graphene sheet. On the other hand, with the reduced εr, the quasiparticle gap is found to decrease instead of increase like in most of semiconductor nanostructures. As a result, it is revealed that the relationship of ?ex with the quasi-particle gap deviates largely from the linear one previously reported for graphene and many other two-dimensional materials.
关键词： excitonic states,dielectric environments,phosphorene quantum dots,scaling rules,configuration interaction approach
更新于2025-09-23 15:19:57
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Phosphorene as H <sub/>2</sub> S and CH <sub/>4</sub> Gas Sensor
摘要： First-principle calculations within density functional theory are carried out to investigate the adsorption of various gas molecules, including hydrogen sulfide and methane on two-dimensional monolayer phosphorene in order to fully exploit the gas sensing capabilities. The adsorption properties of different molecules in the environment on monolayer phosphorene base material is discussed in terms of the Mulliken charge transfer, energy band gap, adsorption energy. The prominent adsorption sites of methane, hydrogen sulfide, water, and oxygen on monolayer phosphorene are investigated at an atomistic level. Based on the results the transport properties of monolayer phosphorene exposed to these gas molecules are investigated both in zigzag and armchair direction using non-equilibrium Green function tuned with density functional theory. The results show that using both directions simultaneously as gas sensing can be an effective technique to distinguish hydrogen sulfide and methane gas molecules from others and demonstrate great selectivity.
关键词： phosphorene,methane,Green function,density functional theory,transport properties,device,hydrogen sulfide,gas sensors
更新于2025-09-23 15:19:57