Fully stretchable and skin-mountable ionic-gated organic phototransistors based on elastomeric semiconductor and dielectric

Abstract

Soft optoelectronics that can be naturally conformable to human skins for noninvasive light-tissue interplays are inspiring for the realization of human–machine interactions, health monitoring, and soft robotics. Advances in material and structural engineering have been made to realize various skin-like electronics/optoelectronics. However, there still exist great challenges such as procedure complexity and high-power dissipation that seriously impede practical applications for these devices. In this work, we demonstrate a fully stretchable and skin-mountable ionic-gated organic phototransistor with an ultra-low power dissipation of 3 nW, high sensitivity up to 103, and a mechanical stretchability of ε = 20%. The phototransistor is composed of an elastomeric ionic gate dielectric layer with ultrahigh capacitance over 1 μF/cm2 and high stretchability up to ε = 50%. Strain-insensitive photodetection of the device is achieved by the nanoconfinement effect existing inside the intrinsically stretchable photoactive semiconductor layer via blending elastic and insulative polymers into an organic bulk heterojunction. Combining with its pronounced electromechanical properties, the stretchable photodetector can be conformable to various body parts for real-time and noninvasive monitoring on different pulse-waves, demonstrating the ability of low-cost and in-home supervision on chronic diseases in daily life.