Thermoelectric characteristics of nanocomposites made of HgSe and Ag nanoparticles for flexible thermoelectric devices

We synthesized thermoelectric nanocomposites by mixing HgSe nanoparticles (NPs) and Ag NPs in a solution and investigated the thermoelectric properties of the nanocomposite thin films on flexible plastic substrates. The X-ray diffraction patterns and the X-ray photoelectron spectra of the nanocomposites demonstrate that cation-exchange reactions occurred spontaneously in the mixed solution of HgSe and Ag NPs and that the HgSe NPs were completely converted to Ag₂Se when the Ag NP content was 20 vol.%. The maximum power factor and the thermoelectric figure of merit were obtained as 75 μW/mK² and 0.043 at 300 K, respectively, when the Ag NP content was 10 vol.%, which is 100 times higher than that of HgSe NP thin films. In addition, the mechanical stability of the thermoelectric nanocomposite film was confirmed through repeated bending tests.