Intrinsically Stretchable Fiber‐Shaped Organic Solar Cells

Fiber‐shaped organic solar cells (FOSCs) with superior mechanical stretchability are strong candidates for portable and wearable electronic power supplies. The high flexibility and stretchability enable the device stably to fit the body and avoid performance loss when the device deforms with irregular body movements. The reported FOSCs with the metal wire–based core electrode already exhibit the ideal flexibility; however, due to lacking stretchable fiber electrodes, the FOSCs with the merit of intrinsic stretchability are rarely reported. Herein, the intrinsically stretchable fiber electrode is demonstrated with robust stretchability and high conductivity for stretchable FOSCs. With the stretchable core electrode, the fabricated FOSCs show superior intrinsic stretchability, remaining more than 90% of the initial efficiency under the stretch strain within 30%. When the stretch strain is released, the device can almost regain 100% of its initial performance. The device's performance maintains stable and even undergoes hundreds of stretching–releasing cycles. Herein, the excellent application potential of intrinsically stretchable FOSCs in wearable electronics is exhibited.