Photonic Absorption Research Articles

In1 − xGaxAs Double Metal Gate-Stacking Cylindrical Nanowire MOSFET for Highly Sensitive Photo Detector

This paper proposed a highly sensitive Double Metal Gate-stacking Cylindrical Nanowire-MOSFET (DMG CL-NWMOSFET) photosensor by using In1 − xGaxAs. For the best control of short channel effects (SCEs), a double metal gate has been utilized and for efficient photonic absorption, III-V compound has been utilized as channel material. The currently available Conventional Filed-Effect-Transistors (CFET) based photosensor have been used threshold voltage as parameter for the calculation of sensitivity, but in the proposed photosensor, change in subthreshold current has been used as the detecting parameters for sensitivity (Iillumination/Idark). The scientifically electrons study and the photo-conductive characteristics of In1 − xGaxAs CL-NWMOSFET are taken through Silvaco Atlas Tools with two work-functions 4.83 eV and 4.41 eV of metal 1 and metal 2 respectively. After the analysis of In1 − xGaxAs dual Metal Gate Stacking Cylindrical NWMOSFET responds to detectable spectrum (~ 450 nm), incidents light with constant, reversible and fast response by responsivity (4.3 mAW− 1), high Iillumination/Idark (1.36 * 109) and quantum-efficiency (1.12 %). The obtained results of In1 − xGaxAs DMG CL-NWMOSFET based photodetectors have the potential in optoelectronics applications.

Remarkable photoluminescence enhancement of CsPbBr3 perovskite quantum dots assisted by metallic thin films

Abstract All-inorganic cesium lead halide perovskite quantum dots have recently received much attention as promising optoelectronic materials with great luminescent properties and bright application prospect in lighting, lasing, and photodetection. Although notable progress has been achieved in lighting applications based on such media, the performance could still be improved. Here, we demonstrate that the light emission from the perovskite QDs that possess high intrinsic luminous efficiency can be greatly enhanced by using metallic thin films, a technique that was usually considered only useful for improving the emission of materials with low intrinsic quantum efficiency. Eleven-fold maximal PL enhancement is observed with respect to the emission of perovskite QDs on the bare dielectric substrate. We explore this remarkable enhancement of the light emission originating from the joint effects of enhancing the incident photonic absorption of QDs at the excitation wavelength by means of the zero-order optical asymmetric Fabry–Perot-like thin film interference and increasing the radiative rate and quantum efficiency at the emission wavelength mediated by surface plasmon polaritons. We believe that our approach is also potentially valuable for the enhancement of light emission of other fluorescent media with high intrinsic quantum efficiency.

Photodegradation of organic dyes and antibacterial activity of Escherichia coli and Staphylococcus aureus by ZnO nanoparticles under UVA radiation

ABSTRACT Zinc oxide (ZnO) nanoparticles were successfully prepared in solutions with the pH of 10 (S-pH10), 11 (S-pH11) and 12 (S-pH12) by sonochemical method combined with calcination. Phase, morphology and photo-emission were characterised by X-ray powder diffraction, Fourier transform infrared spectroscopy, photoluminescence spectroscopy and field emission scanning electron microscopy. UV-visible analysis indicated the photonic absorption of S-pH10, S-pH11 and S-pH12 with 3.55, 3.51 and 3.54 eV direct band gaps, including the BET analytical specific surface areas of 4.73, 6.90 and 9.14 m2/g, respectively. ZnO was tested for photodegradation of methylene blue rhodamine B and methyl orange dyes under UVA radiation. In this research, S-pH12 has the highest photodegradation efficiency. ZnO also tested for antibacterial activity against Escherichia coli and Staphylococcus aureus growth induced by UVA radiation. S-pH10 has the highest antibacterial activity against S. aureus of 97.4 ± 0.20% but S-pH12 has the highest antibacterial activity against E.coli of 35.7 ± 0.10%.

Single-step, wash-free digital immunoassay for rapid quantitative analysis of serological antibody against SARS-CoV-2 by photonic resonator absorption microscopy

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the cause of Coronavirus Disease 2019 (COVID-19), poses extraordinary threats and complex challenges to global public health. Quantitative measurement of SARS-CoV-2 antibody titer plays an important role in understanding the patient-to-patient variability of immune response, assessing the efficacy of vaccines, and identifying donors for blood transfusion therapy. There is an urgent and ever-increasing demand for serological COVID-19 antibody tests that are highly sensitive, quantitative, rapid, simple, minimally invasive, and inexpensive. In this work, we developed a single-step, wash-free immunoassay for rapid and highly sensitive quantitative analysis of serological human IgG against SARS-CoV-2 which requires only a single droplet of serum. By simply incubating 4 μL human serum samples with antibody-functionalized gold nanoparticles, a photonic crystal optical biosensor coated with the recombinant spike protein serves as a sensing platform for the formation of sandwich immunocomplex through specific antigen–antibody interactions, upon which the detected IgG molecules can be counted with digital precision. We demonstrated a single-step 15-min assay capable of detecting as low as 100 pg mL−1 human COVID-19 IgG in serum samples. The calculated limit of detecting (LOD) and limit of quantification (LOQ) is 26.7 ± 7.7 and 32.0 ± 8.9 pg mL−1, respectively. This work represents the first utilization of the Activate Capture + Digital Counting (AC + DC)-based immunoassay for rapid and quantitative analysis of serological COVID-19 antibody, demonstrating a route toward point-of-care testing, using a portable detection instrument. On the basis of the sandwich immunoassay principle, the biosensing platform can be extended for the multiplexed detection of antigens, additional IgGs, cytokines, and other protein biomarkers.

Electromagnetic Modelling of Heterogeneous Photocatalys for the Determination of the Photonic Absorption Speed in a Solar Collector in v

Electromagnetic Modelling of Heterogeneous Photocatalys for the Determination of the Photonic Absorption Speed in a Solar Collector in v

Spill-SOS: Self-Pumping Siphon-Capillary Oil Recovery.

Oil spills remain a worldwide challenge and need emergency "spill-SOS" actions when they occur. Conventional methods suffer from complex processes and high cost. Here, we demonstrate a solar-heating siphon-capillary oil skimmer (S-SOS) that harvests solar energy, gravitational potential energy, and solid surface energy to enable efficient oil spill recovery in a self-pumping manner. The S-SOS is assembled by an inverted U-shape porous architecture combining solar-heating, siphon, and capillary effects, and works without any external power or manual interventions. Importantly, solid surface energy is used by capillary adsorption to enable the self-starting behavior, gravitational potential energy is utilized by siphon transport to drive the oil flow, and solar energy is harvested by solar-thermal conversion to facilitate the transport speed. In the proof-of-concept work, an all-carbon hierarchical architecture (VG/GF) is fabricated by growing vertically oriented graphene nanosheets (VGs) on a monolith of graphite felt (GF) via a plasma-enhanced method to serve as the U-shape architecture. Consequently, an oil-recovery rate of 35.2 L m-2 h-1 is obtained at ambient condition. When exposed to normal solar irradiation, the oil-recovery rate dramatically increases to 123.3 L m-2 h-1. Meanwhile, the solar-thermal energy efficiency is calculated to be 75.3%. Moreover, the S-SOS system presents excellent stability without obvious performance-degradation over 60 h. The outstanding performance is ascribed to the enhanced siphon action, capillary action, photonic absorption, and interfacial heating in the plasma-made graphene nanostructures. Multiple merits make the current S-SOS design and the VG/GF nanostructures promising for efficient oil recovery and transport of energy stored in chemical bonds.

Beyond lotus: Plasma nanostructuring enables efficient energy and water conversion and use

Over millions of years, natural evolution created intricate plant microstructures to most effectively convert and use energy and water. Here we use one-step plasma carbonization and surface nanostructuring of microscopic textures of sacred lotus (Nelumbo nucifera), to dramatically surpass its natural performance in light harvesting, water transport and evaporation. The plasma exposure produces vertically-oriented graphenes (VGs) on the lotus micro-textured surfaces (lotus/VG), without any external carbon source. The nanostructures exhibit high photonic absorption of 99.2% (~twice the pristine lotus), customized centralized water pathway, run-through channels and super-hydrophilicity for ultrafast water transport (~5 times the pristine lotus), and potential for scalable, low cost production. The lotus/VG evaporator exhibits a high solar energy conversion efficiency (~90%) at 1 sun, competitive with synthetic materials. Furthermore, the lotus/VG nanostructures are applied for sludge drying and wastewater treatment, demonstrating great potential of this nanotechnology-enhanced natural material for renewable solar energy utilization.

Digital-resolution detection of microRNA with single-base selectivity by photonic resonator absorption microscopy

Circulating exosomal microRNA (miR) represents a new class of blood-based biomarkers for cancer liquid biopsy. The detection of miR at a very low concentration and with single-base discrimination without the need for sophisticated equipment, large volumes, or elaborate sample processing is a challenge. To address this, we present an approach that is highly specific for a target miR sequence and has the ability to provide "digital" resolution of individual target molecules with high signal-to-noise ratio. Gold nanoparticle tags are prepared with thermodynamically optimized nucleic acid toehold probes that, when binding to a target miR sequence, displace a probe-protecting oligonucleotide and reveal a capture sequence that is used to selectively pull down the target-probe-nanoparticle complex to a photonic crystal (PC) biosensor surface. By matching the surface plasmon-resonant wavelength of the nanoparticle tag to the resonant wavelength of the PC nanostructure, the reflected light intensity from the PC is dramatically and locally quenched by the presence of each individual nanoparticle, enabling a form of biosensor microscopy that we call Photonic Resonator Absorption Microscopy (PRAM). Dynamic PRAM imaging of nanoparticle tag capture enables direct 100-aM limit of detection and single-base mismatch selectivity in a 2-h kinetic discrimination assay. The PRAM assay demonstrates that ultrasensitivity (<1 pM) and high selectivity can be achieved on a direct readout diagnostic.

Scalable Production of Integrated Graphene Nanoarchitectures for Ultrafast Solar-Thermal Conversion and Vapor Generation

Solar-thermal conversion is a key technology in harvesting solar energy for a diverse range of applications including water vapor generation. However, simultaneously ultrafast and highly efficient solar-thermal conversion and scalable fabrication of materials and devices to achieve such performance in practical applications still remain the key unmet challenges. Here we report a hierarchical nanoarchitecture that integrates vertically oriented graphene nanosheets and highly porous graphene aerogel to achieve ultrafast solar-thermal response (a temperature increase of 169.7°C within 1 s), resulting from superior photonic absorption and excellent thermal insulation. Through engineering surface water pathways and minimizing interfacial thermal resistances, ultrafast solar-thermal response (reaching 100°C within 34 s) and simultaneously high energy efficiency (89.4%) for saturated vapor generation at 10 sun is achieved. Importantly, we demonstrate high-throughput, scalable fabrication of the unique nanoarchitecture. Ultrafast medical sterilization is demonstrated as a potential practical application of this green, nanotechnology-enhanced system for large-scale solar energy harvesting.

Impact of electron surface scattering on spectroscopy of periodic dielectric-metal multilayers

We study the effect of surface electron scattering inside metal layers on photonic spectrum, transmissivity, reflectivity, and absorption of periodic dielectric-metal structures in the infrared frequency range. We demonstrate that consideration of finite probability of nonspecular scattering of the conduction electrons by metal layer boundaries is essential: an increase in diffusivity of the metal layer boundaries can lead to disappearance of some Fabry–Perot resonant peaks and substantially alter the shape of the transmission, reflection, and absorption spectra, which gradually transform to virtually flat plateaus. The presented study can be used for interpretation of experimental data on scattering of electromagnetic waves by dielectric-metal multilayers under a lack of detailed information on the state of the metal layer boundaries.

Suppressing elaton drifts

suppressing elaton drifts

A new electromagnetic model for determining the speed of photon absorption in a photocatalytic process for wastewater treatment

In the following work a new mode of operation is presented, as a continuation of the research developed on the elaboration of an electromagnetic model for the determination of the speed of photonic absorption in a solar collector in V (V - collector) (Ramos et al. 2017). The electromagnetic characteristics of the fluid in the suspension will be studied, such as electric permittivity, magnetic permeability, electrical conductivity and frequency of incident light. Likewise, the time variable is included as the innovation in the model to obtain the factors of the phase and the attenuation of the electromagnetic wave that penetrates the suspending medium and the photocatalytic process. For the model, an opto-geometric analysis of the V collector was used, which was studied and contrasted with the literature (Bandala et al. 2004).

The Highest and Lowest Photonic Bandwidths, Absorption Coefficients and Field Localizations among Common 1D Quasiperiodic Structures Containing Graphene and Silicon Dioxide

By employing the transfer matrix method, we report the terahertz spectral properties of graphene induced photonic band gap in four types of common one-dimensional quasiperiodic structures based on double-period, Fibonacci, Thue-Morse and Cantor sequences with approximately the same number of layers. In this paper, a graphene monolayer is sandwiched between two adjacent dielectric slabs. It is found that due to the presence of graphene in each structure, an additional gap (GPBG) is emerged. The upper band edge of GPBG moves to the higher frequencies and gets enlarged, as the chemical potential and incident angle increase. The biggest and the smallest bandwidths belong to the Cantor and double-period sequences. Also, the height of the absorption peak at the GPBG edge goes up as the temperature, graphene thickness and damping factor increase. Moreover, the highest and lowest field localizations exist in the Cantor and Fibonacci structures, respectively. Some other features are presented in the results section.

Optical properties of InN/GaN quantum dot superlattice by changing dot size and interdot spacing

Abstract InN-based III nitride quantum dot (QD) technology has attracted much attention for extended potential applications in photonic devices covering a broad spectrum compared to conventional semiconductors. In this research we have investigated electronic transitions in InN/GaN QD super-lattice structure (QDSL) from valence band (VB) to intermediate band (IB) and from IB to conduction band (CB), which cause the inter and intra band photonic absorption, leading to higher photo-generated current. The ground state energy, absorption coefficient and hence the overall device efficiency dependence on position and width of QDSL have been calculated. The time-independent Schrodinger equation with effective mass approximation in three dimensions is resolved by using Kronig-Penny approximation. The ground state energy is E0 = 1.29 eV, first excited state energy is E1 = 1.9 eV and second excited state energy is E2 = 2.4 eV in a period up to 10 QD layers. Range of transition energy is 197–1415 meV between VB and IB and CB, for which absorption coefficient is 3.5 × 105 µm−1.

Orange-red fluorescent polymer nanocomposite films with large stokes shift: An opto-electronic exercise

Herein, we report the successful fabrication of orange-red fluorescent polymer nanocomposite (PNC) hybrids, that envisage efficient photon management and appreciable UVA-protection, besides high design flexibilities and ease of self-cleaning. The visibly transparent PNC thick films were developed via aqueous solution casting of -OH backboned poly (vinyl alcohol) (PVA) with nanostructured sodium zincate (Na2ZnO2). The as developed PNC films offer appreciable photonic down-conversion of high energy UVA-radiations to relatively lower energy Orange-red light via fluorescent emission. The optical band gap studies reveal a direct band gap relationship with valence band maxima and conduction band minima occurring at same wave vectors. While, static contact angle measurements support nanofiller induced wettability transitions (hydrophilic to near hydrophilic). The fluorescence spectral (excitation and emission) studies of PVA/Na2ZnO2 NC films validate a promisingly large Stokes shift (~245 nm), which visualises a fair separation between the photonic absorption and emission bands, that may further aid an exponential minimization of optical losses due to re-absorption. The thermogravimetric studies support their excellent thermal stabilities. The relatively large Stokes shift, appreciable thermal stability and excellent UV harvesting ability of PVA/Na2ZnO2NC films construct them as competent luminescent down-shifting (LDS) materials for possible solar cell applications.

Ratiometric immunoassays built from synergistic photonic absorption of size-diverse semiconducting MoS2 nanostructures

Liquid-exfoliated MoS2 nanostructures are good candidates as ratiometric-based sensors. They exhibited good resolvable distribution-dependent synergistic photonic absorption states as immunoassays.

AI-based global MPPT for partial shaded grid connected PV plant via MFO approach

The photovoltaic (PV) energy production depends on the conditions surrounding the PV array such as irradiance (G), temperature and the array surface state. These factors directly affect the photonic absorption and the productivity of the PV panels. The phenomenon of partial shading condition (PSC) is one of the problems that disturb the proper operation of PV plants. In the recent literature, several algorithms have been developed to solve this problem. This paper principally aims at extensively presenting the PSC problem that had been considered by numerous articles and cited in this paper. Then, the paper presents combination of two techniques, the first one is the Global Maximum Power Point Tracking (GMPPT) for 100 kW array. The second technique is the Distributed Maximum Power point tracking configuration (DMPPT) for 1 MW PV plant under PSC. This combination aims to overcome the drawbacks related to PSC and enhance the PV system performance. A novel technique GMPPT controller is proposed using Moth-Flame Optimization algorithm (MFO) as solution for PSC shading. A comparative study is performed among different MPPT algorithms such as: Classical Incremental Conductance algorithm (IC), Fuzzy Logic approach based on IC (FL), Particles Swarms Optimization method (PSO) and MFO. Simulation results prove the capability of the proposed approach for seeking the GMPPT of the PV array system.

Ideal photonic absorption, emission, and routings in chiral waveguides

Chiral waveguides have recently being become the robust tools to manipulate the transports of photons along the selected directions. By designing the suitable atom–photon chiral couplings we show that the ideal absorption (i.e., approaching the 100% absorption), unidirectional emission (i.e., along only one of the selected directions), and the routing (i.e., without any reflected loss) of single waveguide photon can be implemented conveniently. The dissipative influences on these chiral quantum functions demonstrated here are discussed.

P‐105: Collimating Optical System Made by Band Pass Filter

Collimating light source is important in AR/VR, 3D and other display products. At present, the collimating light source usually adopts micro lens, prism and so on. The structure and manufacturing process is complex. We present new research results for collimating light, which is a novel collimating LCD backlight technology using a photonic crystal and absorption type color film. There are no complex microstructures and collimating effect in the whole plane. We report progress with performance and describe methodology and results from experiment and simulation results. The angle of collimating light can be controlled in 20°.In the future, we'll optimize the structure and use this technology in the field of QDPR and privacy display.

Analysis of triple metal surrounding gate (TM-SG) III–V nanowire MOSFET for photosensing application

In this paper, a low power highly sensitive Triple Metal Surrounding Gate (TM-SG) Nanowire MOSFET photosensor is proposed which uses triple metal gates for controlling short channel effects and III–V compound as the channel material for effective photonic absorption. Most of the conventional FET based photosensors that are available use threshold voltage as the parameter for sensitivity comparison but in this proposed sensor on being exposed to light there is a substantial increase in conductance of the GaAs channel underneath and, thereby change in the subthreshold current under exposure is used as a sensitivity parameter (i.e., Iillumination/IDark). In order to further enhance the device performance it is coated with a shell of AlxGa1-xAs which effectively passivates the GaAs surface and provides a better carrier confinement at the interface results in an increased photoabsorption. At last performance parameters of TM-SG Bare GaAs Nanowire MOSFET are compared with TM-SG core-shell GaAs/AlGaAs Nanowire MOSFET and the results show that Core-Shell structures can be a better choice for photodetection in visible region.