7 research outputs found
Transparent metal electrodes from ordered nanosphere arrays
We show that perforated metal electrode arrays, fabricated using nanosphere
lithography, provide a viable alternative to conductive metal oxides as
transparent electrode materials. The inter-aperture spacing is tuned by
varying etching times in an oxygen plasma, and the effect of inter-aperture
“wire” thickness on the optical and electronic properties of perforated silver
films is shown. Optical transmission is limited by reflection and surface
plasmons, and for these results do not exceed 73%. Electrical sheet resistance
is shown to be as low as 3 Ω ◻−1 for thermally evaporated silver films. The
performance of organic photovoltaic devices comprised of a P3HT:PCBM bulk
heterojunction deposited onto perforated metal arrays is shown to be limited
by optical transmission, and a simple model is presented to overcome these
limitations
3D hierarchically porous magnetic molybdenum trioxide@gold nanospheres as a nanogap-enhanced Raman scattering biosensor for SARS-CoV-2
A multifunctional 3D magnetic molybdenum trioxide@gold nanosphere is deployed as a plug and play biosensor for SARS-CoV-2 spike proteins via ACE2-mediated immunocapture and magnetic-induced nanogap-enhanced Raman scattering (MINERS)
Understanding Anisotropic Plasma Etching of Two-Dimensional Polystyrene Opals for Advanced Materials Fabrication
Anisotropic deformation of polystyrene
particles in an oxygenated
(O<sub>2</sub>/Ar) plasma is observed for radio frequency (rf) plasma
and inductively coupled plasma (ICP). A facile model based on a ratio
of completely isotropic and completely anisotropic etching is presented
to describe the anisotropy of the etching process and is implemented
to determine the height of the spheroid-shaped polystyrene particles.
In our systems, we find the plasma etching to be 54% isotropic in
the rf plasma and 79% isotropic in the ICP. With this model, the maximum
material deposition thickness for nanofabrication with plasma-etched
nanosphere lithography or colloid lithography can be predicted. Moreover,
the etching of polystyrene particles in an oxygenated plasma is investigated
versus the etching time, gas flow, gas composition, temperature, substrate
material, and particle size. The results of this study allow precise
shape tuning during the fabrication of nanostructured surfaces with
size-dependent properties for bionic, medical, and photonic applications