Isoindigo-based conjugated polymers,
PII2T-C6 and PII2T-C8, with carbosilane side chains have been designed
and synthesized for stretchable electronic applications. The carbosilane
side chains offerred a simple synthetic pathway to evaluate long and
branched side chains in high yields and were prepared with a six or
eight linear spacer plus two hexyl or octyl chains after branching.
The studied polymers showed a high charge carrier mobility of 8.06
cm2 V–1 s–1 with an
on/off current ratio of 106 as probed using a top-contact
transistor device with organized solid state molecular packing structures,
as investigated through grazing-incidance X-ray diffreaction (GIXD)
and atomic force microscopy (AFM) technique systematically. The studied
polymers, more attractive, exhibited superior thin film ductility
with a low tensile modulus in a range of 0.27–0.43 GPa owing
to the branched carbosilane side chain, and their mobility was remained
higher than 1 cm2 V–1 s–1 even under a 60% strain along parallel or perpendicular direction
to the tensile strain. Such polymer films, in addition, can be simultaneously
operated over 400 stretching/releasing cycles and maintained stable
electrical properties, suggesting the newly designed materials possessed
great potential for next-generation skin-inspired wearable electronic
application with high charge carrier mobility, low tensile modulus,
and stable device characteristics during stretching.
A laser-induced fluorescence (LIF) technique was applied to the measurements of the temporal and spatial distributions of Ba atoms in the vicinity of the electrode of a fluorescent lamp operated at 60 Hz. Ground-state (61S0) Ba atoms were excited to a 51P1 level (350.1 nm) by a frequency-doubled dye laser beam, and the subsequent fluorescence (51P1–51D2, 582.6 nm) was detected. Over a whole periodic time (16.67 ms), the density of the Ba atoms was found to have two peaks, and the number of Ba atoms emitted in the anode half-cycle was about twofold larger than that emitted in the cathode half-cycle. This difference between the Ba atoms emitted during the anode half-cycle and those emitted during the cathode half-cycle was studied for lamps with different gas pressures. Ba atoms were found to be emitted mainly from the hot spot of the filament electrode. It is suggested that the main factor for Ba atom emission from the electrode is not sputtering by ion bombardment but thermal evaporation.
The loss of Ba atoms from the electrode of a fluorescent lamp was measured while the lamp was operated in the glow and arc discharge modes at 60 Hz. A laser-induced fluorescence (LIF) technique was applied to the measurements of the temporal and spatial distributions of Ba atoms in the vicinity of the electrode. Ground-state (6 1 S 0 ) Ba atoms were excited to a 5 1 P 1 level by a frequency-doubled dye laser beam (350.1 nm), and the subsequent fluorescence (5 1 P 1 -5 1 D 2 , 582.6 nm) was detected. The temporal and spatial distributions of Ba atoms were found to be completely different in the two discharge modes. Temporally; in the arc discharge mode, the density of the Ba atoms was found to have two peaks, and the number of Ba atoms emitted in the anode half-cycle was about twofold larger than that emitted in the cathode half-cycle. In the glow discharge mode, the number of Ba atoms emitted in the anode half-cycle was found to be negligible compared with that emitted in the cathode half-cycle. Spatially; in the arc discharge mode, Ba atoms were found to be emitted mainly from the hot spot of the filament electrode. In the glow discharge mode, Ba atoms were found to be emitted from all parts of the filament electrodes homogeneously. The mechanism of Ba atom loss in both modes was discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.