Kirigami-Inspired Stretchable Silicon Solar Cell Modules as Portable Power Sources

The integration of photovoltaic modules into wearable electronic devices represents a pivotal advancement for enhancing portability and sustainability. Despite their high efficiency and stability, traditional silicon solar modules are brittle, preventing their applications in mechanically flexible and impact-resistant wearable devices. Herein, we present a novel approach to deformable silicon solar cell modules of different sizes utilizing flexible kirigami-structured substrates integrating commercial silicon cells, enabling durability against continuous deformations caused by body movements. For instance, our Module-14-7S2P, consisting of 14 silicon solar cells, exhibits a power output of 37.50 mW while maintaining > 95% power retention of its original power output after 5000 deformation cycles and > 94% power retention after 120 h of water immersion. Furthermore, upon deformation to a 13% strain, this module retains ∼80% of the initial power output, data supported by FEA simulations. Our study provides new possibilities for employing silicon solar cells in wearable applications, accelerating the adoption of sustainable and portable wearable electronic devices powered by solar energy.