Ultrathin few layer oxychalcogenide BiCuSeO nanosheets

Abstract

Layered materials with intrinsically low thermal conductivity are promising candidates for thermoelectric waste heat to electrical energy conversion. Recently bulk form BiCuSeO, a layered oxychalcogenide, has drawn attention for thermoelectric applications. However, synthesis of a two dimensional nanosheet of BiCuSeO and study of its thermoelectric properties have not been explored yet. Here, we present a facile surfactant free low temperature solvothermal synthesis of few layered ultrathin BiCuSeO nanosheets for the first time. Nanosheets of BiCuSeO exhibit a semiconducting band gap of 0.9 eV and p-type conduction. A dense hot pressed pellet of BiCuSeO nanosheets exhibits a superior power factor and lower lattice thermal conductivity compared to that of the bulk sample in the temperature range of 300–723 K.