Photothermal Conversion of Solar Infrared Radiation by Plasmonic Nanoantennas for Photovoltaic-Thermoelectric Hybrid Devices

Abstract

Photovoltaics have become one of the low-cost options for electricity generation. However, the lack of absorption of the near-infrared and infrared solar spectrum intrinsically limits its efficiency. Here, we present an approach for photothermal conversion of solar infrared radiation in photovoltaic-thermoelectric systems using plasmonic nanoantennas. Through numerical calculations-driven shape engineering, we identified Ni diabolo nanoantennas as efficient solar infrared spectrum harvesters. Nanofabrication with electron-beam lithography further revealed its impact on nanoantenna optical properties at the single-nanoantenna level. In the large-scale low-cost approach, however, photothermal surfaces of nanocone plasmonic antennas, made with a simple and robust fabrication process, still deliver a significant 6.1 °C temperature increase under solar infrared illumination. The reported results pave the way toward the development of hybrid photovoltaic-thermoelectric systems with an optimal utilization of the solar spectrum.