Synthesis and thermoelectric characterization of high density Ag2Te nanowire/PMMA nanocomposites

Abstract

N-type thermoelectric nanocomposites based on monoclinic silver telluride nanowires (Ag2Te NWs) and poly(methyl methacrylate) beads were prepared by means of a simple hot compaction technique. Control of Ag2Te NW composition and crystal structure was achieved by tuning the AgNO3 content in the electrolyte while maintaining a fixed reaction time of the topotactic reaction with Te NWs. The curved shapes and high aspect ratios of the Ag2Te NWs were important in fabricating composites of high density in our system and resulted in reduced contact resistance between the nanowires, which was critical in enhancing the composites' electrical and thermoelectric properties. The thermal conductivity of the composites increased somewhat with nanowire content, but all composites had thermal conductivity nearly the same as that of polymeric material. Consequently, figure of merit (ZT) of 0.005 was achieved in a nanocomposite containing 50 wt% Ag2Te NWs at room-temperature.