Buckled Tin Oxide Nanobelt Webs as Highly Stretchable and Transparent Photosensors

Stretchable and transparent inorganic semiconductors play a key role for the next generation of wearable optoelectronics. Achieving stretchability in intrinsically rigid inorganic materials is far more challenging than in polymers and metals. Here, we present a low-cost and scalable strategy to engineer inorganic semiconductors into a buckling open-mesh configuration, by which extraordinary stretchability (≈160%) as well as high optical transparency (>86% at 550 nm) can be realized simultaneously in SnO2 nanofiber webs. Moreover, the mechanical stretchability of SnO2 nanowebs can be further improved along with the optical transparency by precisely controlling the nanofiber density. The as-prepared freestanding nanowebs can be laminated onto curved surfaces by conformal contact. It is demonstrated that the fully exposed SnO2 nanowebs can be used as wearable UV photodetectors, showing reliable optoelectronic performance and remarkable tolerance to repeated complex deformations with body movements.