Supramolecular engineering heteropoly blue/liquid metal adhesive coating for convenient integration into solar...

Solar thermoelectric generators (STEGs) have emerged as a compelling solution for transforming otherwise wasted long-wavelength sunlight into useful electricity. However, the development of existing STEGs has been significantly hindered by challenging interfacial issues between photothermal materials and thermoelectric generators (TEG), including inefficient integration, high interfacial thermal resistance, and poor interfacial stability. Here we explore a kind of all-in-one adhesive coating by integrating photothermal heteropoly blue (HPBs), liquid metal (LM) with natural amino acids via synergistic non-covalent interactions. Within this supramolecular system, HPBs enable efficient broadband solar absorption and heat generation, while amino acids act as a molecular binder, enabling the formation of a robust network. The coordination interactions of LM with HPBs and amino acids ensure the effective loading of LM and rapid thermal conduction, strengthening thermoelectric coupling. This photothermal adhesive can be conveniently integrated with commercial thermoelectric generators (TEGs), establishing adhesion strength of 1.41 MPa that ensures intimate contact with TEGs while minimizing the thermal resistance and instability. Crucially, the fabricated device attains a record-high power density of 426.2 μW·cm^-2 under 1-sun illumination, and sunlight-accelerated self-healing capability. This work presents an innovative strategy for designing high-performance and robust STEG systems.