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

Abstract

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 μV/K in THF and ca. −195 μV/K in water) are measured with a TE power factor of ∼0.05×10−5 μW/mK2 in THF and ∼0.6×10−5 μW/mK2 in water at room temperature. The study opens up the possibility of exploring broad range of molecular design library for newer n-type OTEs.