Abstract
Thermoelectric (TE) materials are of great importance for harvesting thermal energy from waste or solar heat. One of the promising TE materials is copper iodide (CuI), which is nontoxic, earth‐abundant, and has a high Seebeck coefficient at room temperature (RT). The TE performance of CuI nanoparticles (NPs) is found to be further enhanced by appropriate Al‐doping through reducing the particle size and simultaneously enhancing the electrical conductivity by a factor of 10. Al‐doping manifests to enlarge the deviation from stoichiometric composition, namely δ in Cu1‐δI, and can further assist co‐doping of iodine to generate carrier holes. The thermal conductivity is also reduced by Al‐doping and overall, the figure of merit increases from 0.01 for the pure CuI nanocrystals to ≈0.12 at 300 K and ≈0.2 at 385 K, respectively, for the 0.23 mol% Al‐doped NPs. The power generation characteristics of a single leg TE module made up of the 0.23 mol% Al‐doped CuI measured under real‐time conditions firmly indicate its suitability as a TE generator operating near RT.
The thermoelectric (TE) performance of CuI nanoparticles (NPs) was enhanced by Al‐doping through reducing the particle size and simultaneously enhancing the electrical conductivity. At 300 K the figure of merit increased from 0.01 for the pure CuI nanocrystals to ≈0.12 for the 0.23 mol% Al‐doped NPs. The power generation characteristics indicated its suitability as a TE generator operating near room temperature.