Plasmonic Field Effect Research Articles

A Roadmap toward the Thematic Design of Plasmonic Field Effect Transistors: Crossing the Milestones

AbstractRecently, nano‐optics have attracted immense interest among researchers for the design of all‐optical devices to fulfill the ongoing demands of sustainable energy. Plasmonics of nanoscale materials can be employed to manipulate, guide, and convert ambient electromagnetic radiation to elevate the present state‐of‐the‐art in energy technology. To meet the clean energy challenges that lie ahead, it is indispensable to imbue preconceived notions of the electromagnetic configurations emerging from a set of physical observables that define the plasmonic states of the nanosystem. In this work, a set of hypothetical two‐dimensional plasmonic lattices formed with periodically interdigitated gold nanorods having different geometries and orientations is used as a top layer to simulate the carrier densities of field effect transistors (FETs) as a function of their near‐field potentials within the limit of classical electromagnetism. Based on these considerations, theoretically, a set of principles for the strategic design of different symmetric motifs is illustrated that can increase the effective path length of carriers through strong electromagnetic field confinement to achieve the desired enhancement of the photocurrent of a FET. In essence, the work demonstrates a protocol to design a plasmonic top layer for the maximization of gain voltage of an FET by manipulating the on‐chip local field through plasmonic coupling, giving a new pathway to designing plasmonic FETs.

THz detection and amplification using plasmonic field effect transistors driven by DC drain currents

We report on the numerical and theoretical results of sub-THz and THz detection by a current-driven InGaAs/GaAs plasmonic field-effect transistor (TeraFET). New equations are developed to account for the channel length dependence of the drain voltage and saturation current. Numerical simulation results demonstrate that the effect of drain bias current on the source-to-drain response voltage (dU) varies with the device channel length. In a long-channel TeraFET where plasmonic oscillations cannot reach the drain, dU is always positive and rises rapidly with increasing drain current. For a short device in which plasmonic oscillations reach the drain, the current-induced nonuniform electric field leads to a negative response, agreeing with previous observations. At negative dU, the amplitude of the small-signal voltage at the drain side becomes larger than that at the source side. Thus, the device effectively serves as a THz amplifier in this condition. Under the resonant mode, the negative response can be further amplified near the resonant peaks. A new expression of dU is proposed to account for this resonant effect. Based on those expressions, a current-driven TeraFET spectrometer is proposed. The ease of implementation and simplified calibration procedures make it competitive or superior compared with other TeraFET-based spectrometers.

Surface plasmonic catalysis based on molecular optomechanics

Nowadays, researchers find that the surface plasmons can mediate some chemical reactions through the generation of the confined plasmonic field, excited electrons, and local heating effect. In this article we suggest a new surface plasmonic photocatalysis mechanism based on the molecular optomechanics which is not considered before. A reaction kinetic model was established to achieve a quantitative study of catalytic efficiency. The catalytic mechanism is not limited to a specific chemical reaction, all molecules with Raman activity can be accelerated dramatically in reaction. For molecules with different mechanical properties, the corresponding optomechanical catalytic pathway needs to be selected. We hope that this work will provide guidance for achieving strong or even ultrastrong catalyses under specific optical conditions. We further demonstrate that the optomechanical effects can also be used for the deceleration, which provides the possibility to design a highly tunable chemical reaction system. We believe that the quantum photochemistry will be further developed and widely used in future research.

Wet-Chemical Electro-Plasmonic Modulation of Metasurfaced Cell-Electrode Interfaces for Effective and Selective Entropic Killing of Cancer Cells.

Surface plasmons (SPs) of metallic nanostructures excited by optical ways have been extensively utilized for versatile sensing, biomedical, catalysis, and energy conversion applications. Nevertheless, utilizing the electrically excited plasmonic field (effect) of metallic nanostructures (and electrodes) in wet-chemical conditions, for catalytic and energy conversion, especially for potential biological and biomedical applications, is still poorly studied. Herein, we report a conceptual and biocompatible wet-chemical platform and approach to utilize the electrically excited plasmonic field (effect) of metasurfaced plasmonic electrodes (without light irradiation) for cell fate regulation on electrode surfaces. By using self-assembled two-dimensional (2D) ordered-plasmonic AuNP- or Au@SiO2 NP-nanomembrane as a metasurfaced electrode, the cancer cells cultured on it can be selectively and effectively killed (due to the enhanced stimulus current and related entropic effects) via wet-chemical electro-plasmonic modulation (WC-EPM) of the cell-electrode interfaces. Biological conformational and configurational entropic change information from the cell membrane during the WC-EPM of the cell-electrode interface has also been revealed by label-free in situ surface-enhanced Raman spectroscopy. The developed approach and results can be guides for the WC-EPM regulation of biological interfaces to achieve cell fate regulation and disease treatment and is also constructive for the design of 2D plasmonic nanomaterials and devices for efficient electrochemical energy conservation and biomedical applications.

Localized Plasmon Field Effect of Gold Clusters Embedded in Nanoporous Silicon

AbstractCoupling between nanoplasmonics and semiconducting materials can enhance and complement the efficiency of almost all semiconductor technologies. It has been demonstrated that such composites enhance the light coupling to nanowires, increase photocurrent in detectors, enable sub‐gap detection, allow DNA detection, and produce large non‐linearity. Nevertheless, the tailored fabrication using the conventional methods to produce such composites remains a formidable challenge. This work attempts to resolve that deficiency by deploying the immersion‐plating method to spontaneously grown gold clusters inside nano‐porous silicon (np‐Si). This method allows the fabrication of thin films of np‐Si with embedded gold nanoparticles (Au) and creates nanoplasmonic–semiconductor composites, np‐Si/Au, with fractional volume between 0.02 and 0.13 of the metallic component. Optical scattering measurements reveal a distinctive, 200 nm broad, localized surface plasmon (LSP) resonance, centered around 700 nm. Linear and non‐linear properties, and their time evolution are investigated by optically pumping the LSP resonance and probing the optical response with short wavelength infra‐red (2.5 m) light. The ultrafast time‐resolved study demonstrates unambiguously that the non‐linear response is not only directly related to the LSP excitation, but strongly enhanced with respect to bare np‐Si, while its strength can be tuned by varying the metallic component.

Frequency to digital conversion using Si TeraFETs

Our simulations using the validated multisegment simulation program with integrated circuit emphasis (SPICE) model show that the terahertz (THz) spectrometers using plasmonic field effect transistors could be used for the frequency to digital conversion. The THz SPICE unified charge control model that uses the distributed channel resistances, capacitances, and Drude inductances is validated by technology computer-aided design simulations. The THz spectrometers using Si plasmonic field effect transistors (or TeraFETs) determine the frequency of the impinging radiation by measuring the gate bias where the responsivity changes sign. This crossover frequency is sensitive to the channel length and nearly insensitive to the gate bias in the weak and moderate inversion regions. This unique feature allows the use of multiple THz spectrometers with different channel lengths to implement the frequency-to-digital converters in the sub-THz and THz frequency range. The simulations predict the operation frequency from 110 GHz up to 4 THz for the frequency-to-digital converters using Si TeraFETs with feature sizes from 20 to 130 nm.

TCAD Model for TeraFET Detectors Operating in a Large Dynamic Range

We present technology computer-aided design (TCAD) models for AlGaAs/InGaAs and AlGaN/GaN and silicon TeraFETs, plasmonic field effect transistors (FETs), for terahertz (THz) detection validated over a wide dynamic range. The modeling results are in good agreement with the experimental data for the AlGaAs/InGaAs heterostructure FETs (HFETs) and, to the low end of the dynamic range, with the analytical theory of the TeraFET detectors. The models incorporate the response saturation effect at high intensities of the THz radiation observed in experiments and reveal the physics of the response saturation associated with different mechanisms for different material systems. These mechanisms include the gate leakage, the velocity saturation and the avalanche effect.

Nano-plasmonic near field phase matching of attosecond pulses

Nano-structures excited by light can enhance locally the electric field when tuned to plasmonic resonances. This phenomenon can be used to boost non-linear processes such as harmonic generation in crystals or in gases, Raman excitation, and four wave mixing. Here we present a theoretical investigation of the near-field phase matching of attosecond pulses emitted by high-order harmonic generation (HHG) of an atom immersed in a multi-cycle femtosecond infrared laser field and a spatially inhomogeneous plasmonic field. We demonstrate that the spatial inhomogeneity factor of the plasmonic field strongly affects the electron trajectory and recombination time which can be used to control the attosecond emission. For further insight into the plasmonic field effect, we monitor the phase of each quantum path as a function of the inhomogeneity strength. Moreover, we investigate the attosecond emission as a function of near-field phase matching effects. This is achieved by calculating the coherent field superposition of attosecond pulses emitted from various intensities or field inhomogeneities. Finally, far-field and near-field phase matching effects are combined to modulate the harmonic spectral phase towards the emission of a single attosecond pulse.

Long-Range Plasmon Field and Plasmoelectric Effect on Catalysis Revealed by Shell-Thickness-Tunable Pinhole-Free Au@SiO2 Core–Shell Nanoparticles: A Case Study of p-Nitrophenol Reduction

Plasmon-enhanced photocatalysis is an emerging hot field, but the underlying mechanisms are not very clear. The lack of fundamental understanding of the localized surface plasmon resonance (LSPR) induced electromagnetic field enhancement effects on catalysis is an obstacle to the development of general design rules for engineering efficient plasmonic photocatalysts. Herein, we reveal a long-range plasmon field and plasmoelectric effect on catalysis by using p-nitrophenol (also called 4-nitrophenol, 4-NP) as a model reactant and shell-thickness-tunable and pinhole-free Au@SiO2 core–shell nanoparticles (pf-Au@SiO2 NPs) as photocatalysts and sensing probes. The influence of long-range plasmon field and plasmoelectric effect on catalysis was evidenced by both the illumination-wavelength- and shell-thickness-dependent catalytic activities of pf-Au@SiO2 NPs. Impressively, catalytic 4-NP reduction occurs with AuNPs as catalysts, even if the AuNP surfaces were completely isolated and spaced by the insulating and ...

Utilization of surface plasmon resonance of Au/Pt nanoparticles for highly photosensitive ZnO nanorods network based plasmon field effect transistor

Hydrothermally processed highly photosensitive ZnO nanorods based plasmon field effect transistors (PFETs) have been demonstrated utilizing the surface plasmon resonance coupling of Au and Pt nanoparticles at Au/Pt and ZnO interface. A significantly enhanced photocurrent was observed due to the plasmonic effect of the metal nanoparticles (NPs). The Pt coated PFETs showed Ion/Ioff ratio more than 3 × 104 under the dark condition, with field-effect mobility of 26cm2V−1s−1 and threshold voltage of −2.7V. Moreover, under the illumination of UV light (λ = 350nm) the PFET revealed photocurrent gain of 105 under off-state (−5V) of operation. Additionally, the electrical performance of PFETs was investigated in detail on the basis of charge transfer at metal/ZnO interface. The ZnO nanorods growth temperature was preserved at 110°C which allowed a low temperature, economical and simple method to develop highly photosensitive ZnO nanorods network based PFETs for large scale production.

Role of decoration method of gold nanoparticles on the thermal and optical properties of mesoporous silica-Rhodamine 6G hybrids

Nanotechnology offers the potential for creating new optical imaging agents with novel properties which has been used in molecular imaging and photothermal therapy. Mesoporous silica materials have attained great attention in industry due to its high thermal and chemical stability and non toxic behavior. The performance of mesoporous silica materials depends on composition, morphology and structure of made-up materials. The synthesis of mesoporous silica nanoparticles is highly sensitive because the size, morphology and pore structure changes with small change in procedure. Surface modification of mesoporous enables to incorporate metal nanoparticles in to its pores by co-condensation and post-synthesis method and hence an enhancement in optical and thermal properties of mesoporous silica nanoparticles. In the present work, we have synthesized gold nanoparticles incorporated mesoporous silica by three methods such as non functionalized, co-condensation and post-synthesis modification which is denoted as sample I, sample II and sample III. Thermal parameters such as thermal diffusivity and effusivity of the synthesized samples are measured by thermal lens and photoacoustic techniques respectively. From the values of thermal diffusivity and effusivity, thermal conductivity is estimated and a high value of thermal conductivity is obtained for sample II because of the proper encapsulation of gold nanoparticles in mesoporous silica. The influence of Rhodamine 6G concentrations on the thermal parameters of mesoporous silica is also studied which shows that thermal conductivity decreases with the addition of higher concentration of Rhodamine 6G due to the interface thermal resistance effects. In addition, we have investigated the influence of gold nanoparticle incorporated mesoporous silica on the emission properties of Rhodamine 6G and fluorescein dyes. Irrespective of dye concentration, due to plasmonic field effect and non aggregation of dye molecules, the fluorescence signal is enhanced for both dyes with the addition of gold incorporated mesoporous silica.

Monitoring interfacial lectin binding with nanomolar sensitivity using a plasmon field effect transistor

By immobilizing glycopolymers onto the surface of the recently developed plasmonic field effect transistor (FET), the recognition between lectins and surface-immobilized glycopolymers can be detected over a wide dynamic range (10-10 to 10-4 M) in an environment that resembles the glycocalyx. The binding to the sensor surface by various lectins was tested, and the selectivities and relative binding affinity trends observed in solution were maintained on the sensor surface, and the significantly higher avidities are attributed to cluster-glycoside effects that occur on the surface. The combination of polymer surface chemistry and optoelectronic output in this device architecture produces amongst the highest reported detection sensitivity for ConA. This work demonstrates the benefits that arise from combining emerging device architectures and soft-matter systems to create cutting edge nanotechnologies that lend themselves to fundamental biological studies and integration into point-of-use diagnostics and sensors.

Plasmon Field Effect Transistor for Plasmon to Electric Conversion and Amplification.

Direct coupling of electronic excitations of optical energy via plasmon resonances opens the door to improving gain and selectivity in various optoelectronic applications. We report a new device structure and working mechanisms for plasmon resonance energy detection and electric conversion based on a thin film transistor device with a metal nanostructure incorporated in it. This plasmon field effect transistor collects the plasmonically induced hot electrons from the physically isolated metal nanostructures. These hot electrons contribute to the amplification of the drain current. The internal electric field and quantum tunneling effect at the metal-semiconductor junction enable highly efficient hot electron collection and amplification. Combined with the versatility of plasmonic nanostructures in wavelength tunability, this device architecture offers an ultrawide spectral range that can be used in various applications.

Terahertz Sensing Technology

Sensing applications of THz technology include applications for space exploration, detection of concealed objects, explosive identification, and THz cancer detection. This paper will review these and other emerging applications and existing and potential THz sources and detectors, including photonic and electronic THz devices, such as plasmonic field effect transistors capable of detecting and emitting THz radiation. Plasma wave electronics devices demonstrated THz detection using GaAs-based and GaN-based HEMTs, Si MOS, SOI, and FINFETs and FET arrays. This technology has potential to become a dominant THz electronics technology.

Plasmons in spin-orbit coupled two-dimensional hole gas systems

We study the dynamical dielectric function of a two-dimensional hole gas, exemplified on [001]-GaAs and InAs quantum wells, within the Luttinger model extended to the two lowest subbands including bulk and structure inversion asymmetric terms. The plasmon dispersion shows a pronounced anisotropy for GaAs- and InAs-based systems. In GaAs this leads to a suppression of plasmons due to Landau damping in some orientations. Due to the large Rashba contribution in InAs, the lifetime of plasmons can be controlled by changing the electric field. This effect is potentially useful in plasmon field effect transistors as previously proposed for electron gases.

Enhanced Power Conversion Efficiency in PCDTBT/PC70BM Bulk Heterojunction Photovoltaic Devices with Embedded Silver Nanoparticle Clusters

The use of size-controlled Ag nanoparticles (NPs) synthesized by a polyol process in the BHJ shows improved values of Jsc, FF, and the EQE. These results are due to an enhanced light absorption caused by the plasmonic field effect of Ag cluster from NPs and improved charge transport in the active layer. Ag clusters reduce the series resistance and induce an efficient charge transport system in the BHJ active layer.

On the Mechanism of the Plasmonic Field Enhancement of the Solar-to-Electric Energy Conversion by the Other Photosynthetic System in Nature (Bacteriorhodopsin): Kinetic and Spectroscopic Study

We have recently reported Ag nanoparticles (AgNPs) plasmonic field enhancement of the Bacteriorhodopsin (bR) photocurrent observed during its proton pump photocycle in solution. We proposed a mechanism based on the plasmonic field enhancement of the blue light effect which bypasses the slow part of the photocycle and increases the rate of proton production and thus the observed photocurrent. In this present work, we studied the AgNPs plasmonic field effect on the spectroscopy and kinetics of the bR proton pumping photocycle. We examined the blue light effect on both the recovery rate of bR and the decay rate of the M intermediate by using 532-nm short-pulsed laser excitation of bR in the presence of AgNPs and continuous-wave blue light exposure. Our observation showed that the recovery of bR and the decay of the M intermediate are both greatly accelerated in the presence of both AgNPs and blue light simultaneously. This gives support for the proposed mechanism of the enhanced proton current in the presence of AgNPs with a plasmon band in the blue region. It was found experimentally that the 40 nm-AgNPs enhancement of the blue light effect on the decay rate is around 400× larger than that of 8 nm-AgNPs. This is found to be in agreement with the known dependence of the plasmonic field on size and the overlap of the plasmonic extinction band with the absorption band of the M intermediates.

Tuning of plasmon propagation in two-dimensional electrons

It is shown theoretically that the propagation of plasmons can be tuned by an external electric field via spin-orbit interactions in a two-dimensional electron gas formed in a semiconductor heterostructure. This may provide a manageable way of transmitting quantum information in a quantum device. A possible plasmon field effect transistor is proposed.

Gold Nanoparticle Plasmonic Field Effect on the Primary Step of the Other Photosynthetic System in Nature, Bacteriorhodopsin

In regards to the effect of the surface plasmon field of gold nanospheres on the rate of primary steps leading to retinal photoisomerization in the photosynthesis of bacterirhodopsin (bR), it is believed that the light absorption of bR that leads to its retinal isomerization first involves the formation of a highly polar electronic excited state (I460) of the all-trans isomer which strongly polarizes the protein around it. This is followed by its decay to a viibrationally excited 13-cis isomer (J625). The effect of plasmonic field of gold nanospheres of different sizes and concentrations is found to slow down the rate of the isomerization of the polar electronic excited-state to the J625 but has no effect on the vibration relaxation of the isomeric state itself. This is consistent with the electrostatic nature of the plasmonic field.