3 research outputs found
Soft Poly(butyl acrylate) Side Chains toward Intrinsically Stretchable Polymeric Semiconductors for Field-Effect Transistor Applications
PolyÂ(butyl acrylate)
(PBA) side chain equipped isoindigo-bithiophene
(II2T) conjugated polymers have been designed and synthesized for
stretchable electronic applications. The PBA segment possesses low
glass transition temperature and high softness, offering a great opportunity
to improve the mechanical property of semiconducting polymer thin
films that typically contain lots of rigid conjugated rings. Polymers
with 0, 5, 10, 20 and 100% of PBA side chains, named <b>PII2T</b>, <b>PII2T-PBA5</b>, <b>PII2T-PBA10</b>, <b>PII2T-PBA20</b>, and <b>PII2T-PBA100</b>, were explored, and their polymer
properties, surface morphology, electrical characteristics, and strain-dependent
performance were investigated systematically. The series polymers
showed a charge carrier mobility of 0.06–0.8 cm<sup>2</sup> V<sup>–1</sup> s<sup>–1</sup> with an on/off current
ratio over 10<sup>5</sup> dependent on different amounts of PBA chains
as probed using a top-contact transistor device. Moreover, we can
still achieve a mobility higher than 0.2 cm<sup>2</sup> V<sup>–1</sup> s<sup>–1</sup> even if 10% of PBA side chains were added
(i.e., <b>PII2T-PBA10</b>). Such <b>PII2T-PBA</b> polymers,
more attractive, exhibited superior thin film ductility with a low
tensile modulus down to 0.12 GPa (<b>PII2T-PBA20</b>) due to
the soft PBA side chain. The more PBA segment was incroporated, the
lower modulus was reached. The mobility performance, at the same time,
remained approximately 0.08 cm<sup>2</sup> V<sup>–1</sup> s<sup>–1</sup> based on <b>PII2T-PBA10</b> films even under
a 60% strain and could be simultaneously operated over 400 stretching/releasing
cycles without significant electrical degradations. The above results
suggest that the rational design of soft PBA side chains provides
a great potential for next-generation soft and wearable electronic
applications
Isoindigo-Based Semiconducting Polymers Using Carbosilane Side Chains for High Performance Stretchable Field-Effect Transistors
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
cm<sup>2</sup> V<sup>–1</sup> s<sup>–1</sup> with an
on/off current ratio of 10<sup>6</sup> 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 cm<sup>2</sup> V<sup>–1</sup> s<sup>–1</sup> 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