Stretchable Polymer Gate Dielectric with Segmented Elastomeric Network for Organic Soft Electronics

Abstract

Stretchable electronics has emerged as a key technology for human-friendly soft electronic applications. However, the difficulty of preparing stretchable gate dielectrics is a major impediment to the realization of stretchable electronic devices. Here, we present a stretchable polymer gate dielectric for use in stretchable organic thin-film transistors (OTFTs). Our strategy is to form a segmented elastomeric network inside an end-functionalized reactive liquid rubber with a high dielectric constant by using an organosilane cross-linking agent. The developed dielectric layer consists of hard segments of self-organized nanocrystals and soft rubber segments. The nanocrystals distributed in the rubber matrix resist the growth of electrical treeing inside the film and thus significantly increase the dielectric strength and reduce the leakage current density (∼10–8 A cm–2 at 2.0 MV cm–1). The superior insulating properties are maintained well during tensile stretching with moderate strains ε ≤ 30%. Furthermore, fully stretchable OTFTs based on the developed gate dielectric were demonstrated to stably operate without electrical breakdown under stretching of ε ≤ 34%. These results prove that our method is a promising approach to the development of stretchable polymer gate dielectrics.