Achieving thermoelectric improvement through the addition of a small amount of graphene to CuAlO2 synthesized by solid-state reaction

In this work, delafossite CuAlO2 powders with graphene (0.00-0.20 wt%) were synthesized by a solid-state reaction method. X-ray diffraction and transmission electron microscope results indicated that graphene was segregated in CuAlO2 as a split phase, such as composite material. A little addition of graphene content reduces the thermal conductivity and increases the carrier concentration because the graphene generates many point defects and aided carrier-phonon scattering. The CuAlO2 with graphene content of 0.05 wt% shows the maximum electrical conductivity of 470 S/m at 700 K. In addition, the maximum value for ZT of 0.0045 was recorded at 575 K with the graphene/CuAlO2 composite (0.05 wt%). Therefore, in brief, this study has highlighted the benefits of combining delafossite CuAlO2 with a small amount of graphene as a potential route for achieving highly efficient thermoelectric materials.