Direct Fabrication and Performance Evaluation of InGaZnO Thin-Film Electronics on a Flexible Polyurethane Substrate

The direct fabrication of thin-film transistors (TFTs) based on Indium-Gallium-Zinc-Oxide (IGZO) on a flexible polyurethane (PU) substrate is presented. Polyurethane, with its mechanical flexibility, durability, and potential for environmental sustainability, offers a promising platform for flexible electronics. Here, a custom polyurethane film was synthesized and a low-temperature fabrication process (T ≤130<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">◦</sup>C) was developed for the realization of oxide-based electronics on this flexible material. The fabricated TFTs exhibited an effective mobility of 15.3cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>V<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>s<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>, an on/off current ratio exceeding 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup>, and a threshold voltage of 0.8V. Additionally, the devices demonstrated long-term stability, retaining functionality after over 12 years of storage. The performance of the TFTs on PU is also compared to similar devices realized on a variety of other polymer substrates. The results demonstrate the feasibility of integrating IGZO transistors on polyurethane substrates for flexible electronic applications. Hence PU can open up a path towards unobtrusive and environmentally friendly wearable systems exhibiting mechanical adaptability, long-term reliability, or repairability.