Effects of thickness on flexibility and thermoelectric performance of free-standing Ag2Se films

Abstract

Brittle thermoelectric materials are flexible when sufficiently thin. Although film thickness plays an important role in determining flexibility, a thickness-controlled fabrication method for obtaining flexible, free-standing thermoelectric inorganic films has not yet been reported. In this study, a thickness-controlled fabrication method for free-standing Ag2Se films with nanostructured raw materials is proposed. By introducing the post-annealing process, flexible, free-standing Ag2Se films can be obtained. The effect of thickness on the flexibility and thermoelectric performance of the free-standing Ag2Se films was systematically investigated. The thickness did not significantly affect the thermoelectric performance of the free-standing Ag2Se films. Free-standing Ag2Se films with thicknesses of 110 µm or less exhibited excellent flexible properties. However, thicker Ag2Se films exhibited poor flexibility and that might be related with the experimental limitations in the fabrication process. © 2023 The Korean Society of Industrial and Engineering Chemistry