Enhanced thermoelectric performance of BiCuSeO composites with nanoinclusion of copper selenides

BiCuSeO oxyselenide is a promising oxide-based thermoelectric material in the moderate temperature range, but the low electrical conductivity inhibits its further application in the field of thermoelectric materials. In this paper, we report on the effects that composite structures have an enhancement to the electrical conductivity of BiCuSeO. Here, a series of two-phase nanocomposites comprising of BiCuSeO and Cu2Se have been synthesized by SPS. Images obtained via electron microscope reveal that the two constituents form the unique composites while retaining their individual morphological identities. Owing to the composite structure with a highly conductive nanoscale of copper selenides and submicrometer scale BiCuSeO, an enhancement to the thermoelectric performance is achieved. The ZT at 823 K is increased from 0.33 for pristine BiCuSeO to 0.44 by inserting 20 vol% Cu2Se. Our results state that the composite structure is an effective method to enhance the performance of BiCuSeO.