Flexible metal oxide thin-film transistors produced by a nanofiber-to-film process

Abstract

With the rapid technological development of thin-film transistors (TFTs), TFTs based on silicon are facing inherent limitations. Finding suitable materials and developing new techniques for fabricating high-performance TFTs is of paramount importance. In this report, a preparation technique for thin films by electrospinning was proposed, in which the thin films were prepared by the melting of nanofibers at low temperature, termed nanofiber-to-films (NTF). The In₂O₃ and Al₂O₃ thin films were fabricated by a NTF process and acted as the channel and gate dielectric of TFTs, respectively. High performance TFTs based on In₂O₃/Al₂O₃ were demonstrated, including an average field-effect mobility of 13 cm² V⁻¹ s⁻¹, an on/off current ratio of ∼10⁷, and a subthreshold swing of 0.18 V dec⁻¹. Furthermore, the TFTs based on In₂O₃/Al₂O₃ prepared by the NTF process were successfully fabricated on PI substrates. The flexible TFT exhibits an ON voltage of close to 0 V and a subthreshold swing of 0.29 V dec⁻¹. A device array with 4 × 5 units was fabricated and tested, confirming the excellent reproducibility of the flexible TFT. The electrical performance of the flexible TFT after bending cycles was investigated and excellent mechanical stability was demonstrated. The proposed NTF technology provides a promising approach for large-area and low-cost fabrication of flexible oxide electronic devices.