Abbreviated Journal Title
OPTICAL-FIBER; ELECTRICAL-CONDUCTIVITY; POLYCRYSTALLINE SILICON; Multidisciplinary Sciences
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.
Gumennik, Alexander; Wei, Lei; Lestoquoy, Guillaume; Stolyarov, Alexander M.; Jia, Xiaoting; Rekemeyer, Paul H.; Smith, Matthew J.; Liang, Xiangdong; Grena, Benjamin J.-B.; Johnson, Steven G.; Gradečak, Silvija; Abouraddy, Ayman F.; Joannopoulos, John D.; and Fink, Yoel, "Silicon-in-silica spheres via axial thermal gradient in-fibre capillary instabilities" (2013). Faculty Bibliography 2010s. 4063.