Photoelectric coupling enhanced absorbers for boosting thermoelectric generation

Abstract

Solar thermoelectric generation is an advanced technology with potential in renewable and green energy. However, developing stable photothermal materials with low thermal radiation loss still poses challenges for improving thermoelectric output performance. Here, we developed an Al-doping TiO₂ photoelectric coupling enhanced absorber (ATO–PCEA) based on multilayer nanoparticle-enhanced-absorption coatings using magnetron sputtering. With the interference effect of multilayer nanofilms and the sputter-deposited atoms or particles of Al and TiO₂ formed ordered layer-by-layer enlargement nanoparticles that strengthened the electric-field coupling effect, ATO–PCEA has an efficient solar absorptance of 0.942 and a low thermal emissivity of 0.163, significantly increasing the local photothermal temperature. Notably, a solar thermoelectric generation device was constructed by integrating the ATO–PCEA with a thermoelectric element and assisted by a heat dissipation system. Benefitting from its excellent photothermal conversion (PTC) performance, the device generates a power density of 0.536 W/m² under 1.0 sun, which is 28.7 and 1.1 times higher than that of the thermoelectric generator without the photothermal absorber and the blackbody absorber, respectively. This work provides new perspectives and ideas for photothermal performance enhancement and application expansion of absorbers.