Thermoelectric Characteristics of Ultrathin Ag₂Se Films with Durability Against Mechanical Stress.

Abstract

In this study, we investigated thermoelectric materials with durability against mechanical stress using Ag₂Se nanoparticle (NP) thin films and colorless polyimide (CPI) substrates. Ag₂Se NP thin films and CPI substrates were produced by spin-coating, and their thicknesses were 40 nm and 15 μm, respectively. A bendable thermoelectric film with a channel length of 40 μm and a channel area of 1.6 μm² generated a Seebeck voltage of 1.43 mV at a temperature difference of 4.5 K. Owing to the thickness of the extremely thin thermoelectric film and substrate, the mechanical strain was only 0.15% even when the thermoelectric devices were bent with a curvature of 3 mm. Therefore, it was determined that the bendable thermoelectric film was robust against mechanical stress.