Plasmonics最新文献

Optical refractive index biosensors are susceptible devices for the assessment of various blood components like blood plasma, WBCs, hemoglobin, RBCs, and diabetes mellitus. These biosensors play a crucial role in various fields, including environmental monitoring, pharmaceuticals, biomedical research, and health care. These devices are designed to detect specific biological molecules or chemical compounds by converting their interactions into measurable signals. This manuscript recommends a detached cyclic refractive index biosensor (DCRIB) for the determination of five respective kinds of blood components. The high-rise sensitivity (S) count of 1400 nm/RIU has been noticed for blood plasma, the high-rise quality factor (QF) count is 769.23 for RBCs, the high-rise figure of merit (FOM) count is 540.43 for RBCs, and the minimum determination limit count is 0.0004895 for diabetes cell, along with a high-rise determination range count of 1225.43 for RBCs.

This research presents a surface plasmon resonance (SPR) biosensor that incorporates a dual-side polished photonic crystal fiber (PCF). The biosensor uses an external gold (Au) coating as the plasmonic layer to identify changes in the refractive index (RI) of various analytes. Five critical design parameters, including the diameters of the air holes and the thicknesses of both the analyte and gold layers, were optimized using the Taguchi L₈(2⁵) orthogonal array method. The optimization resulted in outstanding spectral and amplitude sensitivities, achieving 1000 nm/RIU and 98.422 RIU⁻¹, respectively. Additionally, Multiple Linear Regression (MLR) and Multi-Layer Perceptron Artificial Neural Network (MLP-ANN) models were employed to predict the sensor’s confinement loss. The findings demonstrate the efficacy of artificial neural networks in providing quick and accurate predictions for various geometric configurations, showcasing their potential in this advanced application. The designed sensor can detect a wide range of analytes (RI range of 1.28–1.44), making it suitable for applications in organic chemical detection, pharmaceutical analysis, and biosensing.

This study outlines the synthesis and analysis of nickel oxide nanoparticles (NiO) that are coated onto porous silicon (PS) to serve in photodetector applications. The synthesis of nickel oxide nanoparticles was achieved by employing pulsed laser ablation in water, while a PS layer was produced through light-assisted electrochemical etching. An investigation is conducted on the optical, structural, and optoelectronics characteristics of NiO-NPs/PS structures, focusing on their dependence on laser energy. The XRD analysis indicates the presence of distinct peaks corresponding to a cubic pattern, signifying the creation of nickel oxide nanoparticles on PS in the produced specimen. The field emission scanning electron microscope investigation verified that the suspension nanoparticles exhibited predominantly a sphere-like shape. The suspension of NiO nanoparticles appeared as an absorption edge at a wavelength of around 275 nm. Furthermore, it was observed that the absorption peaks became stronger with increased laser energy. The optical properties provide that the band gaps of the NiO NPs formed with laser energies between 400 and 800 mJ were identified, ranging from 4.98 to 4.85 eV, respectively. The photodetector measurements indicate that the NiO NPs/PS structures, formed at 700 mJ, exhibited maximum responsivity visible ranges of 0.065 A/W at 400 nm wavelength and 0.137 A/W at 600 nm wavelength. The results indicated that the spectral responsivity, detectivity, and quantum efficiency of the photodetectors comprised of p-NiO NPs/PS/n-Si were significantly associated with the laser energy employed to prepare the NiO NPs. The fabricated detector achieved its highest spectral response when the NiO NPs were prepared at an energy of 700 mJ. The NiO NPs/PS structures fabricated in this research, which integrate NiO NPs with Si nanostructure, suggest significant promise for deployment as highly effective photodetectors.

Two-dimensional (2D) material-based surface plasmon resonance (SPR) sensor is proposed to detect the basal cancer at 633 nm wavelength. This work detects the analyte between refractive index (RI) 1.33 and 1.335 and also detects the particular application, such as normal and cancer basal cells (NBC and CBC), considered for analysis. This sensor consists of BK7 prism, gold (Au), and hafnium diselenide (HfSe₂) materials which analyzed the performance parameters like sensitivity, full width at half maximum (FWHM), detection accuracy (DA), figure of merit (FoM), and penetration depth (PD). The sensitivity through the proposed sensor is maximum at a specific thickness of the Au layer. Calculated values of sensitivity for the proposed sensor are 275.47°/RIU with analyte RI of 1.33–1.335. Moreover, for basal cancer, the maximum sensitivity of 280.06°/RIU is achieved. The proposed sensor with high sensitivity is a suitable structure for the diagnosis of various cancer type applications.

Surface plasmon resonance (SPR) is used in this article to introduce a novel multilayer configuration and investigate its efficacy as a cancer detection sensor. Our proposed structure comprises an analyte-containing sensing layer underneath an alloy (Au–Ag) and a WS₂ layer on top. Utilizing angle interrogation for analysis and a BK7 prism set up in the Kretschmann configuration, SPR is induced. Sellmeier equations are utilized to compute reflectivity and additional parameters of the multilayer design. According to our analysis, the maximum sensitivity of 304°/RIU was achieved with alloy metal and 2*WS₂ layered SPR sensor configuration, which is significantly higher than recent SPR-based sensors at 662-nm wavelength. The proposed sensor measured the refractive index (RI) of the sensing medium (SM) at 1.399, which is a tiny change, and found a penetration depth (PD) of 189.79 nm. The proposed sensor performance parameters for various cancer types, including skin, cervical, and breast cancers, have been examined. The proposed SPR sensor shows a high potential for accurately detecting different biomolecules, as evidenced by the 39.33/RIU FoM achieved at 1.399 RI of SM with 37 nm thickness of alloy metal layer.

Lead-free perovskite solar cells (LFP SCs) emerged as potential alternatives for elaborating high-efficiency eco-friendly photovoltaic systems. However, further improvements in terms of light trapping optimization and short-circuit current should be developed to overcome the efficiency limitation. In this work, a design framework based on coupling plasmon-induced charge separation gold nanoparticles (Au-NPs) and light trapping engineering using back grooves is proposed, to enhance the photovoltaic performance of the CsSnI₃ solar cell. Accurate numerical models based on combined Finite Difference Time Domain (FDTD)-SCAPS calculations are performed including the influence of Au-NPs and back grooves. In addition, particle swarm optimization (PSO) technique is used to boost up the absorption capabilities of the proposed CsSnI₃ solar cell, where the best distribution of Au-NPs (radius = 38 nm, period = 365 nm) and geometry of back grooves (period = 183 nm, height = 76 nm, and width = 190 nm) are successfully selected. The recorded power conversion efficiency of the proposed CsSnI₃ solar cell could achieve 5.75% and a high short-circuit current of 23.3 mA/cm² is reached by considering the optimized structure. Consequently, the obtained high-photovoltaic properties demonstrate the potential of the proposed design strategy for designing efficient LFP SC by exploiting plasmonic effects combined with light management engineering.

This paper presents a plasmonic metamaterial sensor utilizing gold resonator gratings with different radii for the cylindrical gratings. The sensor is simulated using the finite element method (FEM) in the infrared wavelength range of 0.7 to 2.5 µm. The sensor structure consists of six layers, with the gold resonator on the top, beneath it a Ge–Sb–Te (GST) substrate sandwiched between two silicon (Si) substrates and then a MXene substrate sandwiched between two SiO₂ substrates. The design exhibits distinct reflectance characteristics across the proposed range, which is suitable for different sensing applications. A comparison is made between the two states of GST (amorphous and crystalline) to investigate the sensitivity of the device. Geometrical parameters, including the height of GST and Si, are optimized, changing the oblique incident of light, and three types of comparisons are conducted. Firstly, a sensitivity comparison is made between this work and previously published research. Secondly, a quality factor and figure of merit comparison is performed. Lastly, a sensitivity comparison is made between different sensing techniques and the technique employed in this work. After optimizing the design parameters, the device demonstrates the highest detection sensitivity, yielding results of sensitivity equal to 800 nm /RIU. The proposed design-based metamaterial can be utilized as a lab-on-chip sensor.

Herein, plasmonic characteristics of graphene filled waveguide surrounded by chiroferrite medium are analyzed in the THz frequency spectrum. Graphene conductivity is modelled using the Kobo formula, and impedance boundary conditions are employed to compute dispersion relation. The influence of constitutive variables of chiroferrite medium on the propagation behavior of SPP mode is examined. The propagation behavior of SPPs mode is studied by changing the constitutive parameters of chiroferrite medium and graphene features. From numerical results, it is revealed that effective mode index (EMI, phase velocity, graphene conductivity, and EM wave frequency) can be tailored by adjusting chirality, gyrotropy, and graphene features (chemical potential, number of graphene layers) in the THz frequency range. This work may have potential applications in plasmonic community to design the innovative optical sensors, plasmonic platforms, detectors, and surface waveguides in the THz frequency region and provide active control due to additional degree of freedom in graphene and anisotropy of chiral medium.

In order to improve the integration of fiber optic sensors, this paper designs a dual-core three-channel photonic crystal fiber (PCF) optic sensor that can simultaneously measure the refractive index of a liquid, its temperature, and the ambient magnetic field. Based on the PCF as well as SPR principles, the sensor has two D-planes, one coated with PDMS as well as a gold film for detecting temperature and the other coated with a gold film for detecting refractive index and coated with a gold film over the air holes on the side of the core where the refractive index is measured and a magnetic fluid injected into the air holes to detect the magnetic field. The results show a maximum sensitivity of 20,000 nm/RIU for refractive index, a linear sensitivity of 116 pm/Oe for magnetic field, and 5300 pm/°C for temperature when the sample’s refractive index is between 1.36 and 1.42, the temperature is between 0 °C and 50 °C, and the magnetic field is between 20 and 550 Oe. The sensitivity matrix of temperature versus refractive index is also given. The sensor is compact and simple to prepare, providing a new solution for miniaturization and integration of multifunctional photonic devices.

Plasmonic nanoparticles have had a great impact on the enhancement of the absorption of the thin film solar cell. In this study, we propose two core/shell nanoparticles including graphene/Ag and Ag/graphene nanoparticles. For the design of the graphene/Ag nanoparticle, we utilize a graphene quantum dot (GQD) with a diameter of 66 nm as the core and cover it with Ag with a thickness of 1 nm. We compute the permittivity of the GQD based on the Cole–Cole model. For the design of the Ag/graphene nanoparticle, we cover a spherical Ag nanoparticle with a diameter of 66 nm with a graphene layer with a thickness of 1 nm. We model the surface conductivity of the graphene layer based on the Kubo formula. We consider both nanoparticles as homogeneous nanoparticles and obtain their permittivity based on the equivalent dielectric permittivity model. We incorporate these nanoparticles into an optical simulator and extract their scattering cross sections alongside the Ag nanoparticle. The graphene/Ag nanoparticle shows the best scattering performance; meanwhile, Ag nanoparticle has the weakest scattering performance. Then, we design a Si-based thin film solar cell with Ag nanoparticle and compute its characteristics through the FDTD method. Then, we replace the Ag nanoparticle with our nanoparticles. The short-circuit current density (J_sc) of the Si-based cell improves by 26.3% by embedding of Ag nanoparticle in the absorber layer. This improvement increases by embedding of graphene/Ag and Ag/graphene nanoparticles to 35.3% and 36.8%, respectively.