Facile Gram-Scale Synthesis of the First n-type CuFeS2 Nanocrystals for Thermoelectric Applications

The described method enables facile gram scale preparation of CuFeS2 nanocrystals form simple and readily available precursors, exhibiting interesting thermoelectric properties. Exchange of primary organic ligands for inorganic ones using either (NH4)2S or triethyloxonium tetrafuoroborate (Meerwein's salt) resulted in nanocrystals from which n-type bulk thermoelectric materials could be obtained through sintering under pressure. The measured physical properties of the fabricated bulk thermoelectrics depended on the type of inorganic ligands used for the exchange. In particular, materials surface modified with Meerwein's salt showed higher Seebeck coefficient (ǀSǀ = 238 V K-1) as compared to those modified with (NH4)2S whereas the latter exhibited higher electrical conductivity (8500 S m-1) and lower thermal conductivity (0.5 W m-1 K-1), both parameters favorable for thermoelectric applications.