Fabrication of Stretchable and Transparent Core–Shell Polymeric Nanofibers Using Coaxial Electrospinning and Their Application to Phototransistors

Abstract 1D semiconducting nanomaterials are promising candidates for wearable electronic devices, in which variability of form (i.e., flexibility and stretchability) is a crucial factor for achieving stable operation during a user's physical activity. Although many stretchable 1D electronic materials have been suggested, they mainly rely on structural engineering, rather than the intrinsic stretchability of the materials, and hence suffer from electrical instability under mechanical deformation. In this work, stretchable core–shell polymeric nanofibers (NFs) are fabricated using coaxial electrospinning. The stretchable core–shell NFs, which consist of a stretchable core and a semiconducting shell, provide both mechanical robustness and superior electrical properties under external strain. The stretchable core–shell NF‐based transistors show high operational stability at up to 30% mechanical strain. Furthermore, fully stretchable organic field‐effect transistors fabricated using core–shell NFs and stretchable conductors exhibit stable operation and high optical transparency (71% of transmittance at a wavelength of 550 nm). The core–shell NFs also exhibit excellent optoelectronic properties, including a maximum light responsivity ( R ) of 84.2 A W −1 and an external quantum efficiency (EQE) of 178.6%, under illumination at a wavelength of 585 nm. The results demonstrate a viable approach to fabricating wearable electronic devices using stretchable core–shell polymeric NFs.