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A major challenge to increasing bandwidth in optical telecommunications is to encode electronic signals onto a lightwave carrier by modulating the light up to very fast rates. Polymer electro-optic materials have the necessary properties to function in photonic devices beyond the 40-GHz bandwidth currently available. An appropriate choice of polymers is(More)
BACKGROUND Silica nanoparticles (SiNPs) are being formulated for cellular imaging and for nonviral gene delivery in the central nervous system (CNS), but it is unclear what potential effects SiNPs can elicit once they enter the CNS. As the resident macrophages of the CNS, microglia are the cells most likely to respond to SiNP entry into the brain. Upon(More)
Organic field-effect transistors have been developed that function as either n-channel or p-channel devices, depending on the gate bias. The two active materials are alpha-hexathienylene (alpha-6T) and C(60). The characteristics of these devices depend mainly on the molecular orbital energy levels and transport properties of alpha-6T and C(60). The observed(More)
The thiophene oligomer alpha-hexathienylene (alpha-6T) has been successfully used as the active semiconducting material in thin-film transistors. Field-induced conductivity in thin-film transistors with alpha-6T active layers occurs only near the interfacial plane, whereas the residual conductivity caused by unintentional doping scales with the thickness of(More)
Solution processed organic field-effect transistors (OFETs) usually have high on/off ratios but suffer from low mobilities, while transistors based on graphene usually exhibit very high mobilities but low on/off ratios. We demonstrate a straightforward route to solve the challenging problem of enhancing the effective mobility in OFETs while keeping the(More)
A solid-state picosecond laser is used to ablate semiconductor thin films in spatially localized areas, providing an alternative to device isolation strategies based on chemical or ion etching techniques. Field-effect transistors (FETs) of emerging organic and inorganic materials often utilize a continuous semiconductor film and an array of top-contact(More)
Polar orientation of molecules in solids leads to materials with potentially useful properties such as nonlinear optical and electrooptical activity, electrochromism, and pyroelectricity. A simple self-assembly procedure for preparing such materials is introduced that yields multiple polar dye monolayers on solid surfaces joined by zirconium(More)
An n-type pyromellitic diimide polymer composite with in situ microstructure growth of the common element compound SnCl2 reaches power factor of 50-100 μW m-1 K-2, the highest purely n-type polymer composite power factor yet reported. The composite has a gigantic Seebeck coefficient between -4000 and -5000 μV K-1, many times higher than other polymer(More)