Tunable Dimensionality Effects on the Thermoelectric Performance of Solution-Processable Hybrid Tellurium Nanowire Composites*

Hybrid composite materials have demonstrated a high degree of thermoelectric (TE) performance and manage to leverage positive aspects of both their organic and inorganic counter parts such as ease of solution processability, cost effectiveness, conformal geometries and device printability. To date, there is limited understanding of the physical factors underlying high performance in this class of materials. Here, we investigate the impact of ligand chain length on the physical and TE properties of tellurium nanowires (TeNWs) grown in a simple one-pot synthesis. This work reveals the importance of TeNW dimensionality and polydispersity on TE transport in TeNW systems. Using an aqueous chemical modification technique, conductive polymer ligands are affixed to the surface of the top performing TeNWs, resulting in a p-type hybrid composite TE ink system with an optimized power factor of 130 uW/mK². This study provides insight into how synthetic chemistry can provide previously unused tools for optimizing performance and understanding transport in such complex hybrid systems.