Intrinsically Stretchable Organic Solar Cells and Sensors Enabled by Extensible Composite Electrodes

Abstract

Stretchable electrodes are critical to the development of advanced technologies such as human–machine interaction, flexible sensing, and wearable power supply, making them of significant research value. However, the current preparation methods for high-performance stretchable electrodes are complex and inefficient, posing challenges for their large-scale application in the realm of flexible wearables. To address this need, a straightforward and efficient embedding strategy is reported for fabricating stretchable silver nanowire/thermoplastic elastomer composite electrodes (referred to as Strem-AT) utilizing the viscoelasticity and outstanding mechanical properties of polymer elastomers to achieve outstanding extensibility, conductivity, and a smooth surface. These electrodes exhibit excellent tensile behavior, low surface roughness, and stable electrical properties, enabling their successful integration into stretchable sensors and intrinsically stretchable organic photovoltaic cells (IS-OPV). When applied to human skin joints for motion detection, the sensor demonstrates remarkable stretchability and stable signal output. Importantly, the all-polymer IS-OPV exhibits a top-notch power conversion efficiency (PCE) of >12.5% and a PCE80% strain exceeding 50%. Furthermore, even after subjecting high-strain stretching at 50% for 1000 cycles, the IS-OPV can retain 76% of the initial PCE. This study presents a multifunctional stretchable electrode with high repeatability and easy-to-scale fabrication in wearable sensors and photovoltaics.