Silicon-in-silica spheres via axial thermal gradient in-fibre capillary instabilities

The ability to produce small scale, crystalline silicon spheres is of significant technological and scientific importance, yet scalable methods for doing so have remained elusive. Here we demonstrate a silicon nanosphere fabrication process based on an optical fibre drawing technique. A silica-cladded silicon-core fibre with diameters down to 340 nm is continuously fed into a flame defining an axial thermal gradient and the continuous formation of spheres whose size is controlled by the feed speed is demonstrated. In particular, spheres of diameter <500 nm smaller than those produced under isothermal heating conditions are shown and analysed. A fibre with dual cores, p-type and n-type silicon, is drawn and processed into spheres. Spatially coherent break-up leads to the joining of the spheres into a bispherical silicon 'p-n molecule'. The resulting device is measured to reveal a rectifying I-V curve consistent with the formation of a p-n junction.

[1]  E. Arnold,et al.  Electrical conductivity of semi‐insulating polycrystalline silicon and its dependence upon oxygen content , 1981 .

[2]  O. Shapira,et al.  Towards multimaterial multifunctional fibres that see, hear, sense and communicate. , 2007, Nature materials.

[3]  Masashi Nishimura,et al.  The Direct Observation of Grown‐in Laser Scattering Tomography Defects in Czochralski Silicon , 1996 .

[4]  J. Mikkelsen.  The Diffusivity and Solubility of Oxygen in Silicon , 1985 .

[5]  R. Stolen,et al.  Advancements in semiconductor core optical fiber , 2010 .

[6]  W. Gerberich,et al.  Deconfinement leads to changes in the nanoscale plasticity of silicon. , 2011, Nature nanotechnology.

[7]  Pa Buffat,et al.  Physical properties of semi‐insulating polycrystalline silicon. I. Structure, electronic properties, and electrical conductivity , 1993 .

[8]  Lombardo,et al.  Electrical and structural properties of semi-insulating polycrystalline silicon thin films. , 1993, Physical review. B, Condensed matter.

[9]  U. C. Paek,et al.  Physical behavior of the neck-down region during furnace drawing of silica fibers (A) , 1977 .

[10]  Lloyd L. Chase,et al.  Changes in the Electronic Properties of Si Nanocrystals as a Function of Particle Size , 1998 .

[11]  K. Dreyer,et al.  The route to chaos in a dripping water faucet , 1991 .

[12]  S. Sze.  Semiconductor Devices: Physics and Technology , 1985 .

[13]  Shui-Tong Lee,et al.  Electronic structure and optical properties of silicon nanowires: A study using x-ray excited optical luminescence and x-ray emission spectroscopy , 2004 .

[14]  J. Joannopoulos,et al.  In-fiber semiconductor filament arrays. , 2008, Nano letters.

[15]  K. Taira,et al.  Silicon cells: Catching rays , 2010 .

[16]  Frank Morgan,et al.  Proof of the Double Bubble Conjecture , 2000, Am. Math. Mon..

[17]  Ching-Fuh Lin,et al.  Fabrication of crystalline Si spheres with atomic-scale surface smoothness using homogenized KrF excimer laser reformation system , 2009 .

[18]  Steven G. Johnson,et al.  Linear stability analysis of capillary instabilities for concentric cylindrical shells , 2010, Journal of Fluid Mechanics.

[19]  Yogesh Jaluria,et al.  Practical aspects in the drawing of an optical fiber , 1998 .

[20]  R. Stolen,et al.  Silicon optical fiber. , 2008, Optics express.

[21]  Robert F. Cahalan,et al.  Chaotic rhythms of a dripping faucet , 1990 .

[22]  Steven G. Johnson,et al.  Exploration of in-fiber nanostructures from capillary instability. , 2011, Optics express.

[23]  Dirk C. Keene.  Acknowledgements , 1975 .

[24]  Seiji Takeda,et al.  Self-organized chain of crystalline-silicon nanospheres , 1998 .

[25]  Steven G. Johnson,et al.  Structured spheres generated by an in-fibre fluid instability , 2012, Nature.

[26]  P. Mcmurry,et al.  Hypersonic plasma particle deposition of nanostructured silicon and silicon carbide , 1998 .

[27]  Takuo Tanaka,et al.  Comparison of aberration between axicon and lens , 2000 .

[28]  S. Tomotika.  On the Instability of a Cylindrical Thread of a Viscous Liquid Surrounded by Another Viscous Fluid , 1935 .

[29]  Michael J Sailor,et al.  Biodegradable luminescent porous silicon nanoparticles for in vivo applications. , 2009, Nature materials.

[30]  L. Rayleigh.  On The Instability Of Jets , 1878 .

[31]  H. Okamoto.  O-Si (Oxygen-Silicon) , 2007 .

[32]  A. Abouraddy,et al.  Observation of the Plateau-Rayleigh capillary instability in multi-material optical fibers , 2011 .

[33]  F. Meseguer,et al.  Silicon Colloids: From Microcavities to Photonic Sponges , 2008 .

[34]  P. Kroll,et al.  Nano-sized Crystals of Silicon Embedded in Silica Glass: Large Scale Models and Aspects of the Electronic Structure , 2006 .

[35]  Joachim Mayer,et al.  TEM Sample Preparation and FIB-Induced Damage , 2007 .