Fenollosa Esteve, Roberto
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- PublicationMirror-image-induced magnetic modes(American Chemical Society, 2013-01) Xifre Perez, Elisabet; Shi, Lei; Tuzer, Turan Umut; Fenollosa Esteve, Roberto; Ramiro Manzano, Fernando; Quidant, Romain; Meseguer Rico, Francisco Javier; Instituto Universitario Mixto de Tecnología Química; Ministerio de Ciencia e Innovación; Ministerio de Educación y Ciencia; Generalitat ValencianaReflection in a mirror changes the handedness of the real world, and right-handed objects turn left-handed and vice versa (M. Gardner, The Ambidextrous Universe, Penguin Books, 1964). Also, we learn from electromagnetism textbooks that a flat metallic mirror transforms an electric charge into a virtual opposite charge. Consequently, the mirror image of a magnet is another parallel virtual magnet as the mirror image changes both the charge sign and the curl handedness. Here we report the dramatic modification in the optical response of a silicon nanocavity induced by the Interaction with its image through a flat metallic mirror. The system of real and virtual dipoles can be interpreted as an effective magnetic dipole responsible for a strong enhancement of the cavity scattering cross section.
- PublicationGroove-assisted solution growth of lead bromide perovskite aligned nanowires: a simple method towards photoluminescent materials with guiding light properties(Royal Society of Chemistry, 2019-09-01) Rodríguez, Marie-Isabelle; Fenollosa Esteve, Roberto; Ramiro Manzano, Fernando; García-Aboal, Rocío; Atienzar Corvillo, Pedro Enrique; Meseguer Rico, Francisco Javier; Instituto Universitario Mixto de Tecnología Química; Generalitat Valenciana; Fundación Ramón Areces; Ministerio de Economía y Competitividad[EN] High refractive index nanowires are very attractive because of their waveguiding properties and their multiple applications. In this sense, metal halide perovskites, an emerging and appealing optoelectronic material, have also been tailored into nanowire structures. Here, we present an easy, low-cost and versatile method that has made possible to achieve nanowires of controlled and uniform width. The method has been applied here to all-inorganic and hybrid lead bromide perovskite (CsPbBr3 and CH3NH3PbBr3 respectively) materials. The procedure is based on the spin coating of precursor solutions, at room temperature, on a PDMS replica of the periodic grooves and lands of commercially available Compact Disc (CD) or Digital Versatile Disc (DVD) polycarbonate plates. The method can be applied for the synthesis of other material nanowires before being transferred onto other substrates. The obtained CsPbBr3 and CH3NH3PbBr3 nanowires exhibit high photoluminescence and guiding light properties along the material.
- PublicationSpherical silicon photonic microcavities: From amorphous to polycrystalline(American Physical Society, 2016-06-16) Fenollosa Esteve, Roberto; Garín Escrivá, Moisés; Meseguer Rico, Francisco Javier; Instituto Universitario Mixto de Tecnología Química; Ministerio de Economía y Competitividad; Generalitat Valenciana[EN] Shaping silicon as a spherical object is not an obvious task, especially when the object size is in the micrometer range. This has the important consequence of transforming bare silicon material in a microcavity, so it is able to confine light efficiently. Here, we have explored the inside volume of such microcavities, both in their amorphous and in their polycrystalline versions. The synthesis method, which is based on chemical vapor deposition, causes amorphous microspheres to have a high content of hydrogen that produces an onionlike distributed porous core when the microspheres are crystallized by a fast annealing regime. This substantially influences the resonant modes. However, a slow crystallization regime does not yield pores, and produces higher-quality-factor resonances that could be fitted to the Mie theory. This allows the establishment of a procedure for obtaining size calibration standards with relative errors of the order of 0.1%.
- PublicationPorous silicon microcavities: Synthesis, characterization, and application to photonic barcode devices(SpringerOpen, 2012-09-03) Ramiro Manzano, Fernando; Fenollosa Esteve, Roberto; Xifre Perez, Elisabet; Garín Escrivá, Moisés; Meseguer Rico, Francisco Javier; Instituto Universitario Mixto de Tecnología Química; Generalitat Valenciana[EN] We have recently developed a new type of porous silicon we name as porous silicon colloids. They consist of almost perfect spherical silicon nanoparticles with a very smooth surface, able to scatter (and also trap) light very efficiently in a large-span frequency range. Porous silicon colloids have unique properties because of the following: (a) they behave as optical microcavities with a high refractive index, and (b) the intrinsic photoluminescence (PL) emission is coupled to the optical modes of the microcavity resulting in a unique luminescence spectrum profile. The PL spectrum constitutes an optical fingerprint identifying each particle, with application for biosensing. In this paper, we review the synthesis of silicon colloids for developing porous nanoparticles. We also report on the optical properties with special emphasis in the PL emission of porous silicon microcavities. Finally, we present the photonic barcode concept. © 2012 Ramiro-Manzano et al.
- PublicationMultilayer porous silicon spherical Mie resonator photodiodes with comb-like spectral response in the near infrared region(Elsevier, 2022-11-01) Fenollosa Esteve, Roberto; Garín, Moisés; Instituto Universitario Mixto de Tecnología Química; Agencia Estatal de Investigación; Ministerio de Economía, Industria y Competitividad[EN] Silicon microsphere photodiodes constitute optoelectronic devices able to provide resonance-enhanced photo -current not only in the visible but also in the near infrared range by virtue of their associated Mie resonances. They are synthesized by means of a bottom-up process that allows obtaining thousand of devices in a single batch. The microspheres have revealed an internal structural configuration that strongly influences the photo -current response, thus providing an additional degree of freedom for tuning the properties of the photodiodes. Here, devices with a particular internal configuration consisting of a high porous core, a much less porous surrounding layer and a thin non-porous shell, have been studied. They yield comb like peaked photocurrent spectra that have been fitted to a Mie type model. In addition, net energy conversion at 1500 nm has been demonstrated.
- PublicationOctahedral Molybdenum Cluster-Based Single Crystals as Fabry- Perot Microresonators(American Chemical Society, 2022-01-05) Segura-Sanchis, Elena; Fenollosa Esteve, Roberto; Rodríguez, Marie-Isabelle; Molard, Yann; Cordier, Stéphane; Feliz Rodriguez, Marta; Atienzar Corvillo, Pedro Enrique; Instituto Universitario Mixto de Tecnología Química; Generalitat Valenciana; Agencia Estatal de Investigación; Ministerio de Economía, Industria y Competitividad[EN] Single crystals built up from octahedral Mo-6 cluster units, with appropriate geometry and size, constitute Fabry-Perottype optical microcavities with well-defined resonances. Such resonances appear in the VIS-NIR range when performing optical transmittance (OT) or photoluminescence (PL) measurements. They strongly depend on the crystal thickness and on the optical constants of the material, specifically the real and imaginary parts of the refractive index. In this work, the accurate measurement of the crystal thickness is used for the determination of the optical constants by means of a fitting process, and the preferred orientation of the crystals was determined by X-ray diffraction.
- PublicationSilicon Colloids: a new enabling nanomaterial(AIP Publishing, 2011-05-15) Meseguer Rico, Francisco Javier; Fenollosa Esteve, Roberto; Rodríguez, Marie-Isabelle; Xifre Perez, Elisabet; Ramiro Manzano, Fernando; Garin, M.; Tymczenko, Michal Konrad; Instituto Universitario Mixto de Tecnología QuímicaWe have recently developed a new type of silicon structure that we refer to as a silicon colloid. This new material consists of almost perfectly spherical silicon micro- and nanoparticles with a very smooth surface. They are able to trap light very efficiently in a large-span frequency range covering the visible to the far infrared regions. Silicon colloids can be thought of as a completely new material for scientific and technological purposes, with manifold applications covering electronics, photonics, cosmetics, or paints, among others. Here, we report on the synthesis of polycrystalline, amorphous, and porous silicon colloids, as well as their optical properties, some applications concerning light filters, and photonic bonding.
- PublicationMedically Biodegradable Hydrogenated Amorphous Silicon Microspheres(Springer Verlag (Germany), 2011-10) Shabir, Q.; Pokale, A.; Loni, A.; Johnson, D. R.; Canham, L.T.; Fenollosa Esteve, Roberto; Tymczenko, Michal Konrad; Rodríguez, Marie-Isabelle; Meseguer Rico, Francisco Javier; Cros, Ana; Cantarero, Andrés; Instituto Universitario Mixto de Tecnología Química; Generalitat Valenciana[EN] Hydrogenated amorphous silicon colloids of low surface area (<5 m(2)/g) are shown to exhibit complete in-vitro biodegradation into orthosilicic acid within 10-15 days at 37 degrees C. When converted into polycrystalline silicon colloids, by high temperature annealing in an inert atmosphere, microparticle solubility is dramatically reduced. The data suggests that amorphous silicon does not require nanoscale porosification for full in-vivo biodegradability. This has significant implications for using a-Si:H coatings for medical implants in general, and orthopedic implants in particular. The high sphericity and biodegradability of submicron particles may also confer advantages with regards to contrast agents for medical imaging.
- PublicationSilicon particles as trojan horses for potential cancer therapy(BioMed Central, 2014-09-16) Fenollosa Esteve, Roberto; Garcia-Rico, Eduardo; Alvarez, Susana; Alvarez, Rosana; Yu, Xiang; Rodriguez, Isabel; Carregal-Romero, Susana; Villanueva, Carlos; Garcia-Algar, Manuel; Rivera-Gil, Pilar; de Lera, Angel R.; Parak, Wolfgang J.; Meseguer Rico, Francisco Javier; Alvarez-Puebla, Ramon A.; Instituto Universitario Mixto de Tecnología Química; European Commission; Medcom Tech SA; Ministerio de Ciencia e Innovación; Ministerio de Economía y Competitividad; Generalitat Valenciana; Human Frontier Science Program Organization; China Scholarship Council[EN] Background: Porous silicon particles (PSiPs) have been used extensively as drug delivery systems, loaded with chemical species for disease treatment. It is well known from silicon producers that silicon is characterized by a low reduction potential, which in the case of PSiPs promotes explosive oxidation reactions with energy yields exceeding that of trinitrotoluene (TNT). The functionalization of the silica layer with sugars prevents its solubilization, while further functionalization with an appropriate antibody enables increased bioaccumulation inside selected cells. Results: We present here an immunotherapy approach for potential cancer treatment. Our platform comprises the use of engineered silicon particles conjugated with a selective antibody. The conceptual advantage of our system is that after reaction, the particles are degraded into soluble and excretable biocomponents. Conclusions: In our study, we demonstrate in particular, specific targeting and destruction of cancer cells in vitro. The fact that the LD50 value of PSiPs-HER-2 for tumor cells was 15-fold lower than the LD50 value for control cells demonstrates very high in vitro specificity. This is the first important step on a long road towards the design and development of novel chemotherapeutic agents against cancer in general, and breast cancer in particular.
- PublicationOptical properties of organic/inorganic perovskite microcrystals through the characterization of Fabry-Perot resonances(The Royal Society of Chemistry, 2020-09-28) Ramiro Manzano, Fernando; García-Aboal, Rocío; Fenollosa Esteve, Roberto; Biasi, Stefano; Rodríguez, Marie-Isabelle; Atienzar Corvillo, Pedro Enrique; Meseguer Rico, Francisco Javier; Instituto Universitario Mixto de Tecnología Química; Italian Government; GENERALITAT VALENCIANA; MINISTERIO DE ECONOMÍA Y COMPETITIVIDAD[EN] A precise knowledge of the optical properties, specifically the refractive index, of organic/inorganic perovskites, is essential for pushing forward the performance of the current photovoltaic devices that are being developed from these materials. Here we show a robust method for determining the real and the imaginary part of the refractive index of MAPbBr(3) thin films and micrometer size single crystals with planar geometry. The simultaneous fit of both the optical transmittance and the photoluminescence spectra to theoretical models defines unambiguously the refractive index and the crystal thickness. Because the method relies on the optical resonance phenomenon occurring in these microstructures, it can be used to further develop optical microcavities from perovskites or from other optical materials.
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