Ultrasonic synthesis of nanocrystals of metal selenides and tellurides

A mild sonochemical route was used to prepare Bi₂Te₃ nanocrystals, and Bi₂Se₂Te and Bi₂SeTe₂ ternary nano-alloys in aqueous solution; an interfacial mechanism for this sonochemical reaction is discussed. The basic thermoelectric properties (Seebeck coefficient) of the as-prepared nanocrystals were studied, and this simple, easy and efficient synthetic route may further encourage wider application of bismuth telluride-based alloys in solid state thermoelectric cooling devices. Furthermore, the adopted synthetic route was extended to the preparation of other nanocrystals with uniform morphologies, as well as some common but useful semiconductors.