Enhanced Thermoelectric Properties of BiCuSeO Ceramics by Bi Vacancies

Polycrystalline Bi1-xCuSeO (0 ≤ x ≤ 0.05) ceramics were prepared by self-propagating high-temperature synthesis followed by spark plasma sintering method. All the samples correspond with single BiCuSeO phase and high vacancies sample had higher density. The highest power factor of 4.71×10-4 W.m-1.K-2 was obtained by 5% Bi vacancies at 873K, which is about 32% higher than that of the pristine sample. Along with slight reduction of thermal conductivity, the maximum ZT reached 0.68. The results show that vacancy engineering is a promising method for thermoelectric applications of BiCuSeO and related ceramics.