Energy Harvesting from Rectenna Systems

Rectenna systems harness electromagnetic radiation by integrating an antenna with a high‐speed rectifier diode to convert incident waves—ranging from microwaves to infrared—directly into electrical power. Advances in nanofabrication have enabled the scaling of antenna elements to terahertz frequencies, while novel diode architectures have improved rectification at optical wavelengths. Efficient energy harvesting demands precise impedance matching between antenna and diode, minimisation of junction capacitance and resistance, and enhancement of diode responsivity. These systems offer a decentralised power source for low‐power electronics, wireless sensor networks and autonomous microdevices, with potential impact on sustainable energy solutions and the Internet of Things. The global significance lies in the prospect of harvesting ambient electromagnetic energy from sources such as communication networks, thermal emission and solar radiation, reducing reliance on conventional batteries and contributing to more resilient, maintenance‐free energy infrastructures.

Research from Nature Portfolio

Recent studies have demonstrated resonant tunnelling in metal–double–insulator–metal diodes, achieving both low resistance and high responsivity near zero bias by engineering quantum‐well structures within the insulator layers. This breakthrough paves the way for rectennas with more than a two‐order‐of‐magnitude improvement in energy conversion efficiency at terahertz frequencies. Complementary work has focused on metal–insulator–insulator–metal diodes with controlled oxygen‐non‐stoichiometric interfaces, attaining current densities and asymmetry factors orders of magnitude above conventional designs, thereby boosting optical rectenna performance in the infrared regime. Foundational research on nano‐rectennas has further refined antenna geometry—such as bowtie designs with nanometre‐scale gaps and ultrathin oxide rectifiers—to maximise local field enhancement and zero‐bias responsivity for infrared energy harvesting.

Energy Harvesting from Rectenna Systems publication trend

The graph below shows the total number of articles in energy harvesting from rectenna systems across all publications each year (not limited to Nature Index journals).

Technical terms

Rectenna: A device combining an antenna and a rectifying diode to convert electromagnetic radiation into direct current.

Metal–Insulator–Metal (MIM) diode: A rectifier comprising two metal electrodes separated by a thin insulating layer, used for high‐frequency rectification.

Metal–Insulator–Insulator–Metal (MIIM) diode: A variant of MIM diodes with two insulating layers of differing properties to enhance tunnelling characteristics and responsivity.

Resonant tunnelling: A quantum phenomenon in which electrons traverse a double‐insulator barrier at specific energy states, reducing resistance and improving rectification efficiency.

Impedance matching: The process of optimising the antenna and diode interface to maximise power transfer and minimise reflections.

Responsivity: The ratio of output current to incident electromagnetic power, indicating rectifier sensitivity to input signals.

References

1. Combinatorial Optimization of Metal‐Insulator‐Insulator‐Metal (MIIM) Diodes With Thickness‐Gradient Films via Spatial Atomic Layer Deposition. Advanced Electronic Materials (2024).
2. THz Rectennas and Their Design Rules. Electronics (2017).
3. Design, Optimization and Fabrication of a 28.3 THz Nano-Rectenna for Infrared Detection and Rectification. Scientific Reports (2014).
4. Demonstration of resonant tunneling effects in metal-double-insulator-metal (MI2M) diodes. Nature Communications (2021).
5. High-current density and high-asymmetry MIIM diode based on oxygen-non-stoichiometry controlled homointerface structure for optical rectenna. Scientific Reports (2019).
6. Near zero-bias MIIM diode based on TiO2/ZnO for energy harvesting applications. AIP Advances (2019).