Abstract: A first aspect of the disclosure provides for method of synthesizing bismuth-antimony seleno-telluride thermoelectric nanocrystals. The method may comprise: synthesizing an oxidative chalcogen precursor, the synthesizing including: dissolving a metal in acidic deionized water by reacting the metal with a caustic solution in the deionized water to synthesize a first solution, and adjusting at least one of: pH level or a pE level of the first solution; exposing the oxidative chalcogen precursor to a pnictogen precursor to create nanoseeds; and subjecting the nanoseeds to a microwave thereby synthesizing the bismuth-antimony seleno-telluride thermoelectric nanocrystals.