Thermal Emission of Silicon at Near-Infrared Frequencies Mediated by Mie Resonances

[EN] Planck's law constitutes one of the cornerstones in physics. It explains the well-known spectrum of an ideal blackbody consisting of a smooth curve, whose peak wavelength and intensity depend on the temperature of the body. This scenario changes drastically, however, when the size of the emitting object is comparable to the wavelength of the emitted radiation. Here we show that a silicon microsphere (2-3 mu m in diameter) heated to around 800 degrees C yields a thermal emission spectrum consisting of pronounced peaks that are associated with Mie resonances. We experimentally demonstrate in the near-infrared the existence of modes with an ultrahigh quality factor, Q, of 400, which is substantially higher than values reported so far, and set a new benchmark in the field of thermal emission. Simulations predict that the thermal response of the microspheres is very fast, about 15 mu s. Additionally, the possibility of achieving light emission above the Planck limit at some frequency ranges is envisaged.This work was supported by several projects of the Spanish Ministry of Economy and Competitiveness (MINECO), Severo Ochoa program for Centers of Excellence (SEV-2016-0683), MAT2015-69669-PM, ENE2013-49984-EXP, ENE2015-74009-JIN (cofunded by the European Regional Development Fund), and of the Spanish Science, Innovation and Universities, PGC2018-099744-B-100. F.R.-M. thanks the financial contribution of MINECO through the program for young researchers support, TEC 2015 2015-74405-JIN. The authors greatly acknowledge the contribution of Prof. Francisco Meseguer for both the fruitful discussions and the revision of the manuscript, and Prof. Marie Louise McCarrey for careful proofreading of the manuscript.Fenollosa Esteve, R.; Ramiro-Manzano, F.; Garín Escrivá, M.; Alcubilla, R. (2019). Thermal Emission of Silicon at Near-Infrared Frequencies Mediated by Mie Resonances. ACS Photonics. 6(12):3174-3179. https://doi.org/10.1021/acsphotonics.9b01513S3174317961

Porous silicon microcavities: Synthesis, characterization, and application to photonic barcode devices

[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.This work has been partially supported by the Spanish CICyT projects, FIS2009-07812, Consolider CSD2007-046, and PROMETEO/2010/043.Ramiro Manzano, F.; Fenollosa Esteve, R.; Xifre Perez, E.; Garín Escrivá, M.; Meseguer Rico, FJ. (2012). Porous silicon microcavities: Synthesis, characterization, and application to photonic barcode devices. Nanoscale Research Letters. 7:497-1-497-6. https://doi.org/10.1186/1556-276X-7-497S497-1497-6

All-Silicon spherical-Mie-resonator photodiode with spectral response in the infrared region

[EN] Silicon is the material of choice for visible light photodetection and solar cell fabrication. However, due to the intrinsic band gap properties of silicon, most infrared photons are energetically useless. Here, we show the first example of a photodiode developed on a micrometre scale sphere made of polycrystalline silicon whose photocurrent shows the Mie modes of a classical spherical resonator. The long dwell time of resonating photons enhances the photocurrent response, extending it into the infrared region well beyond the absorption edge of bulk silicon. It opens the door for developing solar cells and photodetectors that may harvest infrared light more efficiently than silicon photovoltaic devices that are so far developed.The authors acknowledge financial support from the following projects: FIS2009-07812, MAT2012-35040, network ‘Nanophotonics for Energy Efficiency’ Grant agreement 248855, TEC2012-34397, Consolider 2007-0046 Nanolight, AGAUR 2009 SGR 549 and the PROMETEO/2010/043. We also acknowledge the fruitful discussions with Professor Javier Garcı´a de Abajo.Garín Escrivá, M.; Fenollosa Esteve, R.; Alcubilla, R.; Shi, L.; Marsal, LF.; Meseguer Rico, FJ. (2014). All-Silicon spherical-Mie-resonator photodiode with spectral response in the infrared region. Nature Communications. 5:2-6. https://doi.org/10.1038/ncomms4440S265Schockley, W. & Queisser, H. J. Detailed balance limit of efficiency of pn junction solar cells. J. Appl. Phys. 32, 510–519 (1961).Cao, L. et al. Engineering light absorption in semiconductor nanowire devices. Nat. Mater. 8, 643–647 (2009).Kelzenberg, M. D. et al. Enhanced absorption and carrier collection in Si wire arrays for photovoltaic applications. Nat. Mater. 9, 239–244 (2010).Ünlü, M. S. & Strite, S. Resonant cavity enhanced photonic devices. J. Appl. Phys. 78, 607–639 (1995).Xu, Q., Schmidt, B., Pradhan, S. & Lipson, M. Micrometre-scale silicon electro-optic modulator. Nature 435, 325–327 (2005).Serpengüzel, A., Kurt, A. & Ayaz, U. K. Silicon microspheres for electronic and photonic integration. Photon. Nanostructur.: Fundam. Appl. 6, 179–182 (2008).Kim, S. K. et al. Tuning light absorption in core/shell silicon nanowire photovoltaic devices through morphological design. Nano Lett. 12, 4971–4976 (2012).Yu, L. et al. Bismuth-catalyzed and doped silicon nanowires for one-pump-down fabrication of radial junction solar cells. Nano Lett. 12, 4153–4158 (2012).Fan, Z. et al. Three-dimensional nanopillar-array photovoltaics on low-cost and flexible substrates. Nat. Mater. 8, 648–653 (2009).Wallentin, J. et al. InP Nanowire array solar cells achieving 13.8% efficiency by exceeding the ray optics limit. Science 339, 1057–1060 (2013).Krogstrup, P. et al. Single-nanowire solar cells beyond the Shockley–Queisser limit. Nat. Photon. 7, 306–310 (2013).Fenollosa, R., Meseguer, F. & Tymczenko, M. Silicon colloids: from microcavities to photonic sponges. Adv. Mater. 20, 95–98 (2008).Pell, L. E., Schricker, A. D., Mikulec, F. V. & Korgel, B. A. Synthesis of amorphous silicon colloids by trisilane thermolysis in high temperature supercritical solvents. Langmuir 20, 6546–6548 (2004).Shi, L. et al. Monodisperse silicon nanocavities and photonic crystals with magnetic response in the optical region. Nat. Commun. 4, a.n.1904 (2013).Levine, J. D., Hotchkiss, G. B. & Wammerbacher, M. D. Basic properties of the spheral solar cell. Proc. 22nd IEEE PVSC p1045IEEE: Las Vegas, (1991).Breen, T. L., Tien, J., Oliver, S. R. J., Hadzic, T. & Whitesides, G. M. Design and self-assembly of open, regular, 3D mesostructures. Science 284, 948–951 (1999).Gracias, D. H., Tien, J., Breen, T. L., Hsu, C. & Whitesides, G. M. Forming electrical networks in three dimensions by self-assembly. Science 289, 1170–1172 (2000).Gumennik, A. et al. Silicon-in-silica spheres via axial thermal gradient in-fibre capillary instabilities. Nat. Commun. 4, a.n.2216 (2013).Yamamoto, K. et al. Thin-film poly-Si solar cells on glass substrate fabricated at low temperature. Appl. Phys. A 69, 179–185 (1999).Cesare, G., de, Caputo, D. & Tucci, M. Electrical properties of ITO/crystalline-silicon contact at different deposition temperatures. IEEE Electron Dev. Lett. 33, 327–329 (2012).Eversole, J. D., Lin, H.-B., Huston, A. L. & Campillo, A. J. Spherical-cavity-mode assignments of optical resonances in microdoplets using elastic scattering. J. Opt. Soc. Am. A 7, 2159–2168 (1990).Poruba, A. et al. Optical absorption and light scattering in microcrystalline silicon thin films and solar cells. J. Appl. Phys. 88, 148–160 (2000)