Speaker
Description
In this project, copper selenide compounds (Cu$_2$Se) were synthesized and used as for use as p-type thermoelectric materials. Graphene oxide (GO) at 0.1, 0.5 and 1 wt% concentrations was added in the Cu$_2$Se compounds. Cu$_2$Se was synthesized by a ball mill method, adding GO at various concentrations by crushing and mixing, followed by shaking. It was then hot-pressed to obtain high density bulk pellets. The sample examined by X-ray diffraction (XRD), showed the Cu$_2$Se phase with a cubic structure, but after hot-pressing, an additional monoclinical Cu2Se phase was formed, due to the phase change at temperatures above 400 K. The analysis from the FE-SEM technique showed that the grain size decreased with increasing GO concentrations, corresponding to the carbon content in EDS, which showed the increased carbon content. From thermoelectric properties measurement, it was found that the Seebeck coefficient was positive and tended to increase slightly with GO concentration. Thermal conductivity was decreased with adding GO. The Cu$_2$Se+GO showed the increased the ZT up to 0.8 at 500 °C, at the concentration of 1 wt% GO. However, the ZT was not enhanced significantly compared to the Cu$_2$Se without GO.
