Triggering ZT to 0.32 in metal-organic complex films using n-doping modulation strategy

Metal-organic complexes have emerged as surprising n-type materials with high thermoelectric performance, good air stability, and low cost. In this study, we introduce an n-doping modulation strategy to enhance the thermoelectric performance of copper-based metal-organic complexes. Notably, the (Br-C6H3(I)-NH2)2CuBr2 film presents a maximum power factor of 2,631 μW m−1 K−2, achieving one of the highest values for n-type organic thermoelectric materials. Crucially, the room temperature thermoelectric figure-of-merit (ZT) value is 0.21 and reaches 0.32 at 418 K, positioning it among the highest-performing n-type organic thermoelectric materials. We observe that the high thermoelectric performance of these novel copper-based metal-organic complexes is due to their heavy effective mass and very high band valley degeneracy. This work reveals the significant potential of the n-doping modulation strategy for metal-organic complex semiconductors in developing state-of-the-art thermoelectric materials.