Optimization of Thermoelectric Nanoantenna for Massive High-Output-Voltage Arrays

Area of Science:

• Nanotechnology
• Energy Harvesting
• Infrared Technology

Background:

• Thermoelectric nanoantennas convert infrared (IR) radiation to direct current (DC) without rectifiers.
• Optimizing nanoantenna geometry and array configuration is key to enhancing output voltage (Voc).

Purpose of the Study:

• Introduce a thermoelectric nanoantenna geometry for maximum Voc.
• Propose an optimal series array configuration to boost Voc.
• Enhance IR-DC energy harvesting efficiency through device design.

Main Methods:

• Utilized a finite, open-ended SiO2 substrate (quarter-effective wavelength thickness at 28.3 THz) to create standing waves.
• Optimally positioned nanoantenna arrays on the substrate to maximize temperature difference (ΔT).
• Performed numerical simulations with a linearly polarized incident wave (1.42 W/cm² power density).

Main Results:

• A single optimized nanoantenna on a 35 µm × 35 µm substrate yielded ΔT of 64.89 mK and Voc of 1.75 µV.
• A 5 × 6 nanoantenna array on a 150 µm × 75 µm substrate achieved a total Voc of 40.18 µV (1.34 µV per element).
• The array demonstrated a voltage responsivity (β) of 0.77 V/W, exceeding previous designs.

Conclusions:

• The optimized thermoelectric nanoantenna array offers high stability and ease of fabrication.
• The device is suitable for manufacturing large-scale arrays for high-output IR-DC energy harvesting.
• Achieved performance matches or surpasses suspended thermoelectric antenna arrays.