Pyrite Bismuth Telluride Heterojunction for Hybrid Electromagnetic to Thermoelectric Energy Harvesting

TL;DR

This paper presents a novel pyrite-bismuth telluride heterojunction that efficiently converts electromagnetic energy from RF signals into electrical energy through thermoelectric effects, enabling scalable energy harvesting for IoT devices.

Contribution

The work introduces a new heterostructure combining pyrite and bismuth telluride for hybrid electromagnetic-thermoelectric energy harvesting, demonstrated with simple fabrication and supported by simulations.

Findings

Achieved a 46°C temperature rise under 35 MHz RF at 1 W input.

Generated a peak power density of approximately 13 mW/cm².

Validated heat transport and interfacial thermoelectric performance with MD and DFT simulations.

Abstract

The rapid proliferation of wireless networks and connected devices has led to pervasive electromagnetic (EM) energy dissipation into the environment, an underutilized resource for energy harvesting. Here, we demonstrate a pyrite (FeS$_2$)-bismuth telluride (Bi$_2$Te$_3$) heterojunction that enables hybrid electromagnetic-to-thermoelectric energy conversion. Fabricated via a simple cold-press compaction of powders, the heterojunction forms a Schottky interface at FeS$_2$, facilitating efficient RF absorption and localized heating. This heat is harvested by Bi$_2$Te$_3$ through thermoelectric conversion. Under 35~MHz RF irradiation at 1~W input power, the device achieved a local temperature rise of 46~$^\circ$C and a thermal gradient of 5.5~K across the Bi$_2$Te$_3$, resulting in a peak power density of approximately 13~mW/cm$^2$. Molecular dynamics (MD) simulations and density functional theory (DFT) calculations further elucidate the heat transport behavior and interfacial thermoelectric performance. This work introduces a new class of heterostructures for RF-responsive energy harvesting, offering a scalable route toward self-powered IoT and wireless sensing systems.