Fabrication of Diamond Nanowires for Quantum Information Processing Applications

We present a design and a top-down fabrication method for realizing diamond nanowires in both bulk single crystal and polycrystalline diamond. Numerical modeling was used to study coupling between a Nitrogen Vacancy (NV) color center and optical modes of a nanowire, and to find an optimal range of nanowire diameters that allows for large collection efficiency of emitted photons. Inductively coupled plasma (ICP) reactive ion etching (RIE) with oxygen is used to fabricate the nanowires. Drop-casted nanoparticles (including $\mathrm{Au}$, $\mathrm{SiO_{2}}$ and $\mathrm{Al_2O_3}$) as well as electron beam lithography defined spin-on glass and evaporated $\mathrm{Au}$ have been used as an etch mask. We found $\mathrm{Al_2O_3}$ nanoparticles to be the most etch resistant. At the same time FOx e-beam resist (spin-on glass) proved to be a suitable etch mask for fabrication of ordered arrays of diamond nanowires. We were able to obtain nanowires with near vertical sidewalls in both polycrystalline and single crystal diamond. The heights and diameters of the polycrystalline nanowires presented in this paper are \unit[\approx1]{\mu m} and \unit[120-340]{nm}, respectively, having a \unit[200]{nm/min} etch rate. In the case of single crystal diamond (types Ib and IIa) nanowires the height and diameter for different diamonds and masks shown in this paper were \unit[1-2.4]{\mu m} and \unit[120-490]{nm} with etch rates between \unit[190-240]{nm/min}.Comment: 11 pages, 26 figures, submitted to Diamond and related Materials; http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWV-4Y7MM1M-1&_user=10&_coverDate=01%2F25%2F2010&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=6dc58b30f4773a710c667306fc541cc

Dielectric Breakdown Strength of Regenerated Silk Fibroin Films as a Function of Protein Conformation

Derived from Bombyx mori cocoons, regenerated silk fibroin (RSF) exhibits excellent biocompatibility, high toughness, and tailorable biodegradability. Additionally, RSF materials are flexible, optically clear, easily patterned with nanoscale features, and may be doped with a variety bioactive species. This unique combination of properties has led to increased interest in the use of RSF in sustainable and biocompatible electronic devices. In order to explore the applicability of this biopolymer to the development of future bioelectronics, the dielectric breakdown strength (<i>E</i>_bd) of RSF thin films was quantified as a function of protein conformation. The application of processing conditions that increased β-sheet content (as determined by FTIR analysis) and produced films in the silk II structure resulted in RSF materials with improved <i>E</i>_bd with values reaching up to 400 V/μm