Localized RF Heating-Driven Thermoelectric Power Generation in Natural Galena (PbS)

Efficient thermoelectric power generation requires a temperature difference across the active material, which can be created through localized or transient heating. Here, we show that radio frequency (RF) excitation induces strong localized heating at a metal–galena (PbS) junction, enabling thermovoltage generation and electrical power output from an earth-abundant semiconductor. RF irradiation in the 35–45 MHz range produces a temperature difference of ∼32 K under ambient conditions, yielding a measurable RF-induced thermovoltage and an effective device-level thermopower of ∼5.8 mV/K. This apparent value exceeds the intrinsic Seebeck coefficient of PbS due to interfacial contributions, band bending, and the highly localized thermal profile rather than any intrinsic modification of the material. The device delivers ∼250 μW of output power and achieves an RF-to-electricity conversion efficiency of ∼15%, based on absorbed RF power. Molecular dynamics simulations corroborate the presence of localized RF heating and provide insight into thermal transport within PbS. These findings demonstrate localized RF heating as a promising mechanism for thermovoltage generation and power production in simple, earth-abundant materials, offering potential for ambient electromagnetic energy harvesting.