Stable Room Temperature Thermoelectric Properties in a Supramolecular Assembly of an n-Type Naphthalene-diimide-based Amphiphile

Organic thermoelectric materials (OTEs) are in huge demand for their flexibility and robustness in applications of internet-of-things, wearables, and health monitoring devices. While choices of p-type OTEs are widespread, there is still lack of stable (in air) n-type systems to pair. Naphthalene-diimides (NDIs), due to the presence of the planar-structured electron-deficient aromatic ring offer promising electron-deficient building blocks to construct air-stable n-type semiconducting devices. Herein, an amphiphile derivative (cNDI-1) is reported for two-dimensional supramolecular assembly, and consequently TE measurements are carried out in a fully calibrated and standardised custom-built Seebeck (S) set-up. Promising S values (ca. -237 mu V/K in THF and ca. -195 mu V/K in water) are measured with a TE power factor of similar to 0.05x10(-5) mu W/mK(2) in THF and similar to 0.6x10(-5) mu W/mK(2) in water at room temperature. The study opens up the possibility of exploring broad range of molecular design library for newer n-type OTEs.