Plasmonic Sensor Based on Dielectric Nanoprisms

Elshorbagy, Mahmoud H.; Cuadrado, Alexander; Alda, Javier

doi:10.1186/s11671-017-2347-7

Cited by 13 publications

(20 citation statements)

References 36 publications

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“…In most of the commercially available SPR devices, the excitation of SPR is based on a Kretschman configuration, which requires light-prism coupling under oblique incidence [6]. As an improvement, the excitation of SPRs in normal incidence conditions is key to simplify the optical scheme, ease the illumination and acquisition signal system, allowing a lower cost solution [7][8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

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

2019

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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.

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Section: Introductionmentioning

confidence: 99%

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

2019

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“…This material appears at the wavevector matching condition for those SPR at the top of the metal layer included in the calculation of the effective index of refraction as a combination of the indices of refraction of three materials: buffer layer (n BL ), nano-triangles (n g ), and analyte (n a ). This dielectric buffer layer also controls the coupling between the diffracted wave and the SPR mode, and improves the final response of the device [14]. In this case, SPRs are only excited on top of the metal layer.…”

Section: Model Design and Optimizationmentioning

confidence: 99%

“…This is key for sensing applications because the interaction of light is strongly affected by the optical characteristics of the exposed media [15]. The narrow spectral response, due to SPR excitation, becomes even narrower if these resonances interact with guided or grating modes to generate hybrid resonances [24], [13], [14], [15].…”

Section: Introductionmentioning

confidence: 99%

“…On top of this dielectric layer, a periodic grating made of dielectric nano-triangles route the light towards the metal/dielectric interface. This triangular relief also triggers funneling and guiding mechanisms that improve the performance of the devices [14], [29]. Light impinges the structure from the analyte side that is located above the dielectric grating.…”

Section: Introductionmentioning

confidence: 99%

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Ultra-Narrow Spectral Response of a Hybrid Plasmonic-Grating Sensor

et al. 2020

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We configure and analyze a nanostructured device that hybridizes grating modes and surface plasmon resonances. The model uses an effective index of refraction that considers the volume fraction of the involved materials, and the propagation depth of the plasmon through the structure. Our geometry is an extruded low-order diffraction grating made of dielectric nano-triangles. Surface plasmon resonances are excited at a metal/dielectric interface, which is separated from the analyte by a high-index dielectric layer. The optical performance of the refractometric sensor is highly competitive in sensitivity and figure of merit (FOM) because of the the ultra-narrow spectral response (below 0.1 nm). Moreover, it is operative within a wide range of the index of refraction (from 1.3 till 1.56), and also works under normal incidence conditions.

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“…Plasmonic resonances are widely employed to enhance the performance of refractometric sensors; they are usually revealed by monitoring the spectral response (spectral interrogation), or by modifying the angle of incidence (angular interrogation) [12,13]. Kretschmann and Otto configurations-well-known techniques-require reflectance to be measured angularly under oblique incidence conditions [14][15][16].…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2020

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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.

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Plasmonic Sensor Based on Dielectric Nanoprisms

Cited by 13 publications

References 36 publications

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

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

Ultra-Narrow Spectral Response of a Hybrid Plasmonic-Grating Sensor

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

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