Selenium nanomaterials enabled flexible and wearable electronics

Selenium (Se), as an intriguing chalcogenide semiconductor, has traditionally been used for solar energy harvesting. The recent development of nanoscience and nanotechnology has enabled a myriad of Se nanomaterials with compelling structures and unique features. Compared with other chalcogens, Se nanomaterials possess anisotropic crystalline structure, intrinsic chirality, and high reactivity, as well as unique optical, electrical, photoconductive, and piezoelectrical properties. The integration of these Se nanomaterials with technologically important materials, such as conductors and semiconductors, over flexible, bendable, stretchable, and highly curved substrates offer a new generation of Se nanomaterial-based flexible and wearable electronics. In this mini review, we survey the recent scientific and technological breakthroughs in Se nanomaterials-enabled flexible and wearable electronics. We highlight the synthesis, fabrication, morphologies, structure, and properties (optical, electrical, optoelectrical, photovoltaic, and piezoelectric) of Se nanomaterials as well as their integration into innovative functional devices that deliver higher forms of applications across smart sensing, health care, and energy domains. We conclude with a critical analysis of existing challenges and opportunities that will trigger the continued progress of the field.