Thermoelectric transportation in indium doped bismuth oxyselenide (Bi_2-xIn_xO₂Se) ceramics consolidated by conventional isostatic pressing

Thermoelectric (TE) devices are gaining significant consideration from the renewable energy community because of their environment friendliness. In this study, a series of indium (In) doped bismuth oxyselenide (Bi_2-xIn_xO₂Se) ceramics has been prepared through a facile hydrothermal route followed by consolidation into bulk pellets using Isostatic Pressing. The effects of indium doping on crystal structure, microstructure and thermoelectric properties have been systematically investigated. The detailed structural characterization reveals the partial substitution of In into the lattice of Bi₂SeO₂ at Bi-site along with the formation of a secondary phase (Bi₄O₈Se). The highest power factor (PF) of 17.40 µW/mK² has been achieved at 500 K. In-doping has introduced defects into the lattice to offer strong scattering site for phonons.