Conventional sintered Cu_(2-x)Se thermoelectric material

As the featured material of the superionic thermoelectric(TE)material family,copper-chalcogenide Cu_(2-x)Se is attracting growing research interest for its excellent TE performance derived from the satisfactory power factor and the ultra-low thermal conductivity induced by the superionic effect.Various efforts have been made and proved to be effective to further enhance the TE performance for Cu_(2-x)Se.However,this material is still far from the application stage,which is mainly due to concerns regarding control of the properties and the costly complex fabrication technology.Here we report a scalable pathway to achieve high-performance and tunable Cu_(2-x)Se,utilizing conventional sintering technology and copper(Cu)-vacancy engineering with an effective mass model.The figure of merit zT is a competitive value of 1.0 at 800 K for the optimized binary Cu_(2-x)Se,based on the precise modeling prediction and Cu-vacancy engineering.The changes in TE properties of Cu_(2-x)Se under heating-cooling cycle tests are also revealed.Our work offers the referable method along with the decent parent material for further enhancement of TE performance,paving a possible route for the application and industrialization of Cu_(2-x)Se TE materials.