Nanowire Thermoelectrics: An Approach for Enhancing ZT,

Abstract : The overall objectives of the AASERT project are to develop an approach for the controlled synthesis of single crystal, one-dimensional (1D) nanowires of the Bi2Te3 family of thermoelectric materials, and to characterize the potentially unique electronic properties of these 1D systems. To achieve these goals we will (1) develop synthetic procedures, which were initiated as part of our current ONR project on nanorod- superconductor composites, to prepare Bi2Te3 nanowires and (2) exploit existing scanning tunneling microscopy facilities and expertise to characterize the nanowire density of electronic states. The combination of systematic synthesis with high-resolution structural and electronic characterization will elucidate the basic factors that control the diameter, aspect ratio, and crystallographic growth direction of Bi2Te3 nanowires, and define the variation and potential enhancements in valence and conduction band edge density of states with nanowire diameter. These studies will thus provide a critical assessment of the possibility of obtaining enhanced thermoelectric figures of merit through material dimensional control.