| The cold sintering process (CSP) is a new sintering technology which is able to densify ceramics below 300℃ with the assistant liquid phase. CSP is not only simple to operate, low in cost, but also energy-saving and consumption-reducing, developing great prospects in preparing bulk thermoelectric materials. In this paper, Bi2Te2.7Se0.3 powder was prepared by a solvothermal method. The corresponding bulk was fabricated by CSP with the addition of 0 wt% liquid phase, 10 wt% H2O, 10 wt% EG and 10 wt% NaOH solution respectively, and then compared with the sample prepared by spark plasma sintering (SPS). XRD pattern shows that all samples are not oxidized by air. The density measurement results show that the density of samples added with NaOH solution or H2O is as high as about 97%, which is about 7% higher than that of sample added with 0 wt% liquid phase. Among all the samples prepared by CSP, the sample added with NaOH solution has the highest ZT value of 0.9 at 375 K, which is higher than that of the sample prepared by SPS from 300 K to 400 K. Our results show that CSP is a very promising method to prepare Bi2Te2.7Se0.3 bulk thermoelectric material. |
