<p>Cu₂Se-based material is an ideal medium and low-temperature thermoelectric material, and the devices made from it can effectively recycle the industrial waste heat between room temperature (RT) and 300&#xa0;°C. In this study, the β-Cu_2+<i>x</i>Se/a-C/CuInSe₂ multilayer films on Si(100) substrate were prepared by alternating sputtering using Cu–Se compound, graphite, and Cu–In–Se compound targets. The structure and thermoelectric properties of the deposited films were characterized. Results showed that RT carrier concentration, carrier mobility, electrical conductivity, and thermal conductivity monotonically decreased, but the Seebeck coefficient and power factor gradually increased with increasing number of amorphous carbon (a-C) layers in deposited multilayer films due to the carrier and phonon scattering of layer interface. It is an effective method to improve thermoelectric properties that the a-C layers are incorporated into β-Cu₂Se/CuInSe₂ multilayer films.</p> Graphical abstract <p></p>