Single-Crystal SnSe Film for High-Performance Flexible Thermoelectric Generators

SnSe-based thermoelectric (TE) materials have emerged as promising candidates for wearable devices and flexible electronics due to their exceptional thermoelectric performance. While SnSe single crystals exhibit superior TE properties, their practical applications in flexible electronics have been hindered by mechanical brittleness and complex processing challenges. In this study, we systematically investigated the inherent anisotropic elastic modulus of single-crystalline SnSe and developed a facile tape-peeling method to fabricate high-quality SnSe films. These films exhibited remarkable flexibility, mechanical stability, and a high-power factor of 24 μW cm –1 K –2 at 300 K. Furthermore, flexible thermoelectric generators based on SnSe films achieved a high normalized power density of 257.4 W m –2 under a temperature gradient (Δ T ) of 60 K. These results not only demonstrate the immense potential of SnSe films for flexible thermoelectric applications but also provide a scalable fabrication approach that offers an alternative pathway for the development of advanced wearable energy-harvesting technologies.