Thermoelectric materials synthesized by self-propagating high temperature synthesis process and methods thereof

A method of preparing a thermoelectric material, comprising:

• 1) weighing powders of reactants including Bi2O3, PbO, Bi, Cu, and Se according to a stoichiometric ratio of Bi2O3:PbO:Bi:Cu:Se=(1−p):3p:(1−p):3:3, where p=0, 0.02, 0.04, 0.06, 0.08 or 0.1, mixing the powders in an agate mortar, and cold-pressing the powders into a pellet;
• 2) sealing the pellet in a silica tube under a pressure of 10−3 Pa, initiating a self-propagating high temperature synthesis (SHS) by point-heating a portion of the pellet wherein, once the SHS starts, a wave of exothermic reactions passes through the remaining portion of the pellet, cooling down the pellet after reaction in air or quenched in salt water to obtain a cooled-down pellet containing Bi1−pPbpCuSe;
• and
• 3) crushing the cooled-down pellet obtained in step 2) into powder, and sintering the powder with plasma activated sintering (PAS) to form a bulk material, wherein parameters of the PAS include a reaction temperature above 670° C. and a reaction pressure of 30 MPa for 5-7 min, and a final product is a BiCuSeO based thermoelectric material.