Porous Silicon Microcavities: Synthesis, Characterization, and Application to Photonic Barcode Devices

F. Ramiro-Manzano; R. Fenollosa; E. Xifré-Pérez; M. Garín; F. Meseguer

doi:10.1186/1556-276X-7-497

Research · Publication & note

Porous Silicon Microcavities: Synthesis, Characterization, and Application to Photonic Barcode Devices

Nanoscale Research Letters · Journal article · 3 September 2012

F. Ramiro-Manzano, R. Fenollosa, E. Xifré-Pérez, M. Garín and F. Meseguer

Nanoscale Research Letters

Volume 7

Issue 1

Article 497

2012

Abstract

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.

How to cite

Initials first

F. Ramiro-Manzano, R. Fenollosa, E. Xifré-Pérez, M. Garín and F. Meseguer. “Porous silicon microcavities: synthesis, characterization, and application to photonic barcode devices.” Nanoscale Res. Lett. 7(1), 497 (2012). DOI: 10.1186/1556-276X-7-497.

Family name first

Ramiro-Manzano, F., Fenollosa, R., Xifré-Pérez, E., Garín, M. and Meseguer, F. “Porous silicon microcavities: synthesis, characterization, and application to photonic barcode devices.” Nanoscale Res. Lett. 7(1), 497 (2012). DOI: 10.1186/1556-276X-7-497.

Article access and reuse

The article is open access under the Creative Commons Attribution 2.0 licence. Figures 3 and 6 are original to this article and are reused under CC BY 2.0. Figures 1, 2, 4 and 5 were reprinted in the article from earlier publications; they are shown here under the verified author-reuse terms of their original RSC, AIP and Wiley sources, with the original publication credited below each figure.

Figures

Figure 1. Optical microscopy images of porous and amorphous silicon microspheres and an SEM image of a porous silicon microsphere.

Figure 1. Microscopy images. (a) Optical image of porous silicon microspheres and (b) optical image of a:Si-H microspheres. Porous silicon microspheres scatter yellow, orange and red colours under white light, whereas a:Si-H microspheres appear black. (c) SEM image of a porous silicon microsphere about 2 μm in diameter.

From R. Fenollosa et al., J. Mater. Chem. 20, 5210–5214 (2010), DOI 10.1039/C0JM00079E. © The Royal Society of Chemistry 2010. Reproduced by an author with acknowledgement.

Figure 2. Optical transmittance spectra and Mie-theory fits for two polycrystalline silicon colloids.

Figure 2. Optical properties of polycrystalline silicon colloids. Optical transmittance (black) and Mie-theory fits (red) of single silicon colloids with diameters Φ = 1885 nm (a) and Φ = 1050 nm (b). Transmittance dips correspond to whispering-gallery modes; the insets show electric-field intensity distributions.

From F. Meseguer et al., J. Appl. Phys. 109, 102424 (2011), DOI 10.1063/1.3581880. © American Institute of Physics. Reused on an author’s personal, non-commercial website with full citation.

Experimental and calculated transmittance spectra of a porous silicon colloid — **Figure 3.** Optical properties of porous silicon colloids. Measured optical transmittance of a 1.910-μm-diameter porous silicon sphere (black curve). The Mie theory fit (red curve) gives a refractive index of 1.8 in all the measured range. The resonant modes are indicated under their corresponding deeps by letters ‘a’ (for transversal magnetic modes) and ‘b’ (for transversal electric modes) and two sub-indexes that account for the different electric field intensity distributions.

Figure 4. Transmittance and photoluminescence spectra of a porous silicon microsphere.

Figure 4. Transmittance (a) and photoluminescence (b) spectra of a porous silicon microsphere about 4.1 μm in diameter. Dips in the transmittance spectrum correspond to photoluminescence peaks associated with the optical resonances of the microcavity.

From F. Ramiro-Manzano et al., Advanced Materials 23, 3022–3025 (2011), DOI 10.1002/adma.201100986. © 2011 Wiley-VCH Verlag GmbH & Co. KGaA. Reused by the authors under Wiley’s contributor reuse terms.

Figure 5. Two photonic barcodes with photoluminescence spectra and optical microscopy images.

Figure 5. Photonic barcodes (a,e) produced by two porous silicon microspheres. Bar positions and widths are determined by the resonances of their photoluminescence spectra (b,f). Optical microscopy images were taken in reflection (c,g) and transmission (d,h).

From F. Ramiro-Manzano et al., Advanced Materials 23, 3022–3025 (2011), DOI 10.1002/adma.201100986. © 2011 Wiley-VCH Verlag GmbH & Co. KGaA. Reused by the authors under Wiley’s contributor reuse terms.

Photoluminescence spectra showing the stability of porous silicon colloids — **Figure 6.** PL spectra of an about 3.4-μm diameter porous silicon colloid. After being immersed in 200-mM NADPH aqueous solution during 1 (bottom spectrum) and 5 h (top spectrum).