Iodide Ion-Assisted Silver-Telluride-Based Nanowires: Morphology Optimization and Efficient Doping for Improved Thermoelectric Application

Abstract

Silver-telluride-based nanowires (STNWs) are promising thermoelectric (TE) materials for room temperature (RT) applications, can be utilized to fabricate flexible TE composites or inks to facilitate TE conversion in various situations. However, current research on doping design and morphology optimization of STNWs is still limited. Such strategies are expected to enhance the TE performance and flexibility, thereby improving the compatibility of STNWs for TE applications. Herein, we report a simple yet efficient iodide ion-assisted strategy for doping design and morphology optimization, significantly enhancing both the TE performance and flexibility of the STNW films. Iodide ions serve dual roles of regulating the chemical transformation process and acting as a effective dopant, ultimately achieving a 1.97-fold increment in the power factor of the STNW films at RT, as well as promoting the formation of a structure of bundles composed of morphology-optimized STNWs, which significantly improves the flexibility of STNW films. On this basis, flexible TE composite films and TE devices are fabricated and systematically evaluated, demonstrating the excellent potential of STNWs for practical applications. This study paves the way for the development of STNW-based TE materials and provides insights for synthesis of other nanostructured TE materials.