Growth of quantum dot coated core-shell anisotropic nanowires for improved thermal and electronic transport

Abstract

Anisotropic nanowires are promising candidates for electronic thermal management due to their unique electrical and thermal properties. However, eco-friendly solution-processed nanomaterials with an elaborate morphology and microstructure for modulating thermal and charge transfer are still a considerable challenge. Herein, we present a simple but effective approach for synthesizing pseudo core-shell nanowires through quantum dot (QD)-like nanostructure coating (p-NW@QD) to generate exceptional electron-phonon transport properties. With the assistance of diphenyl ether as a coordination solvent, high crystallinity lead sulfide NWs can be fabricated with a large aspect ratio together with uniform QD coating. This p-NW@QD exhibits high electronic mobility (30.65 cm2/Vs) as well as a diameter independent low thermal conductivity (1.53 ± 1 W/m K). Direct charge/heat carrier flow measurements and computational simulations demonstrate that the unusual electrical and thermal transport phenomenon is strongly dependent on the fast charge transport through the QD shell, and a slow phonon migration across the Umklapp process dominated NW cores. These findings indicate a significant step toward colloidal synthesis nanostructures for future high-performance nanoelectronics and thermal energy devices.