Tailoring thermoelectric properties of copper selenide through engineering nano/micro-sized particles

Copper selenide has emerged as a promising thermoelectric material due to its unique structural properties and tunable electronic band structure. However, its practical application is hindered by its relatively high thermal conductivity. In this study, we report on the turning of thermal conductivity and thermoelectric energy conversion by preparing a hybrid composite material including nano- and micro-sized Cu2Se. By employing a hydrothermal synthesis method with cetyltrimethylammonium bromide (CTAB) as a surfactant, we successfully synthesized nano-sized Cu2Se particles with uniform size distribution. The incorporation of these nano-sized particles with micro-sized Cu2Se resulted in a significant reduction in thermal conductivity, leading to adjustment of the thermoelectric performances. Our findings provide a promising strategy for designing high-performance thermoelectric materials for waste heat recovery and energy conversion applications in the medium temperature range.