scholarly journals Narrow Absorption in ITO-Free Perovskite Solar Cells for Sensing Applications Analyzed through Electromagnetic Simulation

2019 ◽  
Vol 9 (22) ◽  
pp. 4850 ◽  
Author(s):  
Mahmoud H. Elshorbagy ◽  
Alexander Cuadrado ◽  
Javier Alda
Keyword(s):  
Surface Plasmon ◽  
Active Layer ◽  
Spectral Response ◽  
Index Of Refraction ◽  
Metallic Surface ◽  
Coupling Mechanism ◽  
Selective Absorption ◽  
Surface Plasmon Resonances ◽  
Sensing Applications ◽  
Plasmon Resonances

This work reports on a computational analysis of how a modified perovskite cell can work as a refractometric sensor by generating surface plasmon resonances at its front surface. Metal-dielectric interfaces are necessary to excite plasmonic resonances. However, if the transparent conductor (ITO) is replaced by a uniform metal layer, the optical absorption at the active layer decreases significantly. This absorption enhances again when the front metallic surface is nanostructured, adding a periodic extruded array of high aspect-ratio dielectric pyramids. This relief excites surface plasmon resonances through a grating coupling mechanism with the metal surface. Our design allows a selective absorption in the active layer of the cell with a spectral response narrower than 1 nm. The photo-current generated by the cells becomes the signal of the sensor. The device employs an opto-electronic interrogation method, instead of the well-known spectral acquisition scheme. The sensitivity and figure of merit (FOM) parameters applicable to refractometric sensors were adapted to this new situation. The design has been customized to sense variations in the index of refraction of air between 1.0 and 1.1. The FOM reaches a maximum value of 1005 RIU − 1 , which is competitive when considering some other advantages, as the easiness of the acquisition signal procedure and the total cost of the sensing system. All the geometrical and material parameters included in our design were selected considering the applicable fabrication constrains.

scholarly journals Tuning the Fano Resonance Between Localized and Propagating Surface Plasmon Resonances for Refractive Index Sensing Applications

Plasmonics ◽  
2013 ◽  
Vol 8 (3) ◽  
pp. 1379-1385 ◽  
Author(s):  
Kristof Lodewijks ◽  
Jef Ryken ◽  
Willem Van Roy ◽  
Gustaaf Borghs ◽  
Liesbet Lagae ◽  
...  
Keyword(s):  
Refractive Index ◽  
Surface Plasmon ◽  
Fano Resonance ◽  
Surface Plasmon Resonances ◽  
Refractive Index Sensing ◽  
Sensing Applications ◽  
Plasmon Resonances

scholarly journals Opto-Electronic Refractometric Sensor Based on Surface Plasmon Resonances and the Bolometric Effect

2020 ◽  
Vol 10 (4) ◽  
pp. 1211 ◽  
Author(s):  
Mahmoud H. Elshorbagy ◽  
Alexander Cuadrado ◽  
José Antonio Gómez-Pedrero ◽  
Javier Alda
Keyword(s):  
Surface Plasmon ◽  
Metal Layer ◽  
Spectral Characteristics ◽  
Monochromatic Light ◽  
Index Of Refraction ◽  
Metallic Layer ◽  
Surface Plasmon Resonances ◽  
Plasmon Resonances ◽  
Bolometric Effect ◽  
Low Order

The bolometric effect allows us to electrically monitor spectral characteristics of plasmonic sensors; it provides a lower cost and simpler sample characterization compared with angular and spectral signal retrieval techniques. In our device, a monochromatic light source illuminates a spectrally selective plasmonic nanostructure. This arrangement is formed by a dielectric low-order diffraction grating that combines two materials with a high-contrast in the index of refraction. Light interacts with this structure and reaches a thin metallic layer, that is also exposed to the analyte. The narrow absorption generated by surface plasmon resonances hybridized with low-order grating modes, heats the metal layer where plasmons are excited. The temperature change caused by this absorption modifies the resistance of a metallic layer through the bolometric effect. Therefore, a refractometric change in the analyte varies the electric resistivity under resonant excitation. We monitor the change in resistance by an external electric circuit. This optoelectronic feature must be included in the definition of the sensitivity and figure of merit (FOM) parameters. Besides the competitive value of the FOM (around 400 RIU − 1 , where RIU means refractive index unit), the proposed system is fully based on opto-electronic measurements. The device is modeled, simulated and analyzed considering fabrication and experimental constrains. The proposed refractometer behaves linearly within a range centered around the index of refraction of aqueous media, n ≃ 1.33 , and can be applied to the sensing for research in bio-physics, biology, and environmental sciences.

scholarly journals Surface Plasmon Resonances in Silver Nanostars

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3821 ◽  
Author(s):  
Faustino Reyes Gómez ◽  
Rafael Rubira ◽  
Sabrina Camacho ◽  
Cibely Martin ◽  
Robson da Silva ◽  
...  
Keyword(s):  
Surface Plasmon ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Localized Surface Plasmon ◽  
Surface Plasmon Resonances ◽  
Localized Surface Plasmon Resonances ◽  
Sensing Applications ◽  
Surface Enhanced ◽  
Plasmon Resonances ◽  
Difference Time

The recent development of silver nanostars (Ag-NSs) is promising for improved surface-enhanced sensing and spectroscopy, which may be further exploited if the mechanisms behind the excitation of localized surface plasmon resonances (LSPRs) are identified. Here, we show that LSPRs in Ag-NSs can be obtained with finite-difference time-domain (FDTD) calculations by considering the nanostars as combination of crossed nanorods (Ag-NRs). In particular, we demonstrate that an apparent tail at large wavelengths ( λ ≳ 700 nm) observed in the extinction spectra of Ag-NSs is due to a strong dipolar plasmon resonance, with no need to invoke heterogeneity (different number of arms) effects as is normally done in the literature. Our description also indicates a way to tune the strongest LSPR at desired wavelengths, which is useful for sensing applications.

scholarly journals Exploiting Localized Surface Plasmon Resonances in Subwavelength Spiral Disks for THz Thin Film Sensing

2020 ◽  
Vol 10 (10) ◽  
pp. 3595
Author(s):  
Vasily V. Gerasimov ◽  
Ruslan R. Hafizov ◽  
Sergei A. Kuznetsov ◽  
Pavel A. Lazorskiy
Keyword(s):  
Surface Plasmon ◽  
Low Frequency ◽  
Localized Surface Plasmon ◽  
Surface Plasmon Resonances ◽  
Localized Surface Plasmon Resonances ◽  
Sensing Applications ◽  
Plasmon Resonances ◽  
High Figure ◽  
Sensing Performance ◽  
Good Agreement

In this paper, we studied the sensing performance of metasurfaces comprised by spiral-disk-shaped metallic elements patterned on polypropylene substrates, which exhibited localized surface plasmon resonances in the low-frequency region of the terahertz (THz) spectrum (0.2–0.5 THz). Optimal designs of spiral disks with C-shaped resonators placed near the disks were determined and fabricated. The experimentally measured transmittance spectra of the samples coated with very thin photoresistive layers (d ~ 10−4–10−3 λ) showed good agreement with the simulations. The resonance frequency shift Δf increases with increasing d, while saturating near d = 50 µm. The narrow-band magnetic dark modes excited on symmetrical spiral disks with a 90° C-resonator demonstrated very high figure of merit (FOM) values reaching 1670 (RIU·mm)−1 at 0.3 μm thick analyte. The hybrid high order resonances excited on asymmetrical densely packed spiral disks showed about two times larger FOM values (up to 2950 (RIU·mm)−1) compared to symmetrical distantly spaced spirals that resembled the best FOM results found in the literature for metasurfaces fabricated with a similar technique. The demonstrated high sensing performance of spiral disks is evaluated to be promising for bio-sensing applications in the THz range.

scholarly journals Exploiting Localized Surface Plasmon Resonances in Subwavelength Spiral Disks for THz Thin Film Sensing

2020 ◽  
Author(s):  
Vasily V. Gerasimov ◽  
Ruslan R. Hafizov ◽  
Sergei A. Kuznetsov ◽  
Pavel A. Lazorskiy
Keyword(s):  
Surface Plasmon ◽  
Low Frequency ◽  
Localized Surface Plasmon ◽  
Surface Plasmon Resonances ◽  
Localized Surface Plasmon Resonances ◽  
Sensing Applications ◽  
Plasmon Resonances ◽  
Very High ◽  
Sensing Performance ◽  
Good Agreement

In this paper, we study the sensing performance of metasurfaces comprised by spiral-disk-shaped metallic elements patterned on polypropylene substrates, which exhibit localized surface plasmon resonances in the low-frequency region of the THz spectrum (0.2-0.5 THz). Optimal designs of spiral disks with C-shaped resonators placed near the disks were determined and fabricated. The experimentally measured transmittance spectra of samples coated with very thin photoresistive layers (d ~ 10-4-10-3 λ) showed good agreement with simulations. The resonance frequency shift Δf increases with increasing d, while saturating near d = 50 µm. The narrow-band magnetic dark modes excited on symmetrical spiral disks with a 90⁰-C-resonator demonstrated very high FOM values reaching 1670 [RIU·mm]-1 at 0.3μm-thick analyte. The hybrid high order resonances excited on asymmetrical densely packed spiral disks showed about two times larger FOM values (up to 2950 [RIU·mm]-1) as compared to symmetrical distantly spaced spirals that resembles the best FOM results found in literature for metasurfaces fabricated with a similar technique. The demonstrated high sensing performance of spiral disks is evaluated to be promising for bio-sensing applications in the THz range.

scholarly journals Surface Plasmon Resonances in Sierpinski-Like Photonic Crystal Fibers: Polarization Filters and Sensing Applications

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4654
Author(s):  
William O. F. Carvalho ◽  
J. R. Mejía-Salazar
Keyword(s):  
Refractive Index ◽  
Photonic Crystal ◽  
Surface Plasmon ◽  
Wavelength Range ◽  
Circular Cross Section ◽  
Wide Band ◽  
Surface Plasmon Resonances ◽  
Refractive Index Sensing ◽  
Sensing Applications ◽  
Plasmon Resonances

We investigate the plasmonic behavior of a fractal photonic crystal fiber, with Sierpinski-like circular cross-section, and its potential applications for refractive index sensing and multiband polarization filters. Numerical results were obtained using the finite element method through the commercial software COMSOL Multiphysics®. A set of 34 surface plasmon resonances was identified in the wavelength range from λ=630 nm to λ=1700 nm. Subsets of close resonances were noted as a consequence of similar symmetries of the surface plasmon resonance (SPR) modes. Polarization filtering capabilities are numerically shown in the telecommunication windows from the O-band to the L-band. In the case of refractive index sensing, we used the wavelength interrogation method in the wavelength range from λ=670 nm to λ=790 nm, where the system exhibited a sensitivity of S(λ)=1951.43 nm/RIU (refractive index unit). Due to the broadband capabilities of our concept, we expect that it will be useful to develop future ultra-wide band optical communication infrastructures, which are urgent to meet the ever-increasing demand for bandwidth-hungry devices.

Optical and Morphological Studies of Gold Nano Thin Films on Glass Substrates for Surface Plasmon Resonance Sensors

2019 ◽  
Vol 57 ◽  
pp. 51-57 ◽  
Author(s):  
Mina Mohammadian ◽  
Amir Hossein Sari
Keyword(s):  
Thin Films ◽  
Surface Plasmon ◽  
Surface Plasmon Resonances ◽  
Suitable Candidate ◽  
Glass Substrates ◽  
Morphological Studies ◽  
Sensing Applications ◽  
Plasmon Resonances ◽  
Topological Surface ◽  
Au Thin Films

We have observed surface plasmon resonances (SPR) in Au thin films between 18 nm to 27 nm thick deposited onto glass substrates. The observed resonance angles are between 15.5 to 18.75 degrees, which are lower than predicted theoretical values for thicker films. The shift of resonances with the change of refractive index of surrounding confirms its application for nanobio-sensing. A thorough topological surface analysis and transmitted spectra were performed. Au thin films were annealed in Argon and the analysis repeated and compared with those from pre-annealing. The annealing process will cause a sharper appearance of surface plasmon resonances which will make these thin film devices a more suitable candidate for nanobio-sensing applications.

Sign in / Sign up

Export Citation Format

Share Document