Thermoelectric properties of ITO and SnSe nanowires and Sb[subscript 2]Se[subscript 3] hexagonal nanotubes.

Abstract

The synthesis of multifunctional nanomaterials has received great attention in the last years due to the possibility of integrating multiple functionalities into individual building blocks to enable the fabrication of novel and powerful devices. At the same time, power dissipation is an increasingly important challenge in actual industry, specially with highly miniaturized devices. In this way, thermoelectric materials have been the subject of great attention due to the possibility of interchanging thermal gradients and electric fields, specially in the retrieval of waste heat. This work is a study of the thermoelectric and transport properties of single Indium Tin Oxide (ITO) nanowires with a thermal tolerance of 1300°C, Tin Selenide (SnSe) nanowires with diameters in the range between 110 nm and 1150 nm, and Antimony Selenide (Sb[subscript 2]Se[subscript 3]) hexagonal nanotubes. Their electrical and thermal conductivities, and the Seebeck coefficient were measured in each individual nanowire/nanotube using specialized suspended micro-resistance thermometry devices in the ∼ 120 − 370 K temperature range. The measured properties were correlated to electronic and lattice information obtained with model simulations and phonon’s dynamics.

Conclusions are drawn in each case about the applicability of these materials in energy production and waste heat recovery, the performance of the nanoscale structures as compared with bulk samples, and their advantages and disadvantages. The work about ITO nanowires brings new data about their thermal tolerance and their potential as thermoelectric converters working in harsh environments. The work on SnSe nanowires offers the first study of the thermoelectrical properties of this material in nanowire shape and brings appealing unexpected results about the possible size dependence of their lattice thermal conductivity. The work about Sb[subscript 2]Se[subscript 3] nanotubes shows promising thermoelectric figures of merit and the first comprehensive study of the thermoelectric properties of such structures.