Abstract
There has been an ongoing demand of clean and inexpensive energy source for the sustainable growth of humanity. However, depletion of fossil fuels and fluctuation in oil prices have resulted in a global crisis for increasing the demand of clean and green energy. The world total energy consumption is currently higher than 55,235 TWh, and it grows at a rate of 2.5% annually. The increase in energy demand and decrease in energy supply signifies the urgent need to limit the dependency on fossil fuels and seek renewable sources of energy. The scientific communities and researchers are seeking alternative sources of renewable energy. Infrared (IR) energy harvesting is a promising contribution to sustainable energy demand. There is abundant IR energy available in the environment in the spectrum range from 2 to 11 mu m (in wavelength), having maximum intensity at 10.6 mu m (28.3 THz). The idea is to treat the waste heat as very high oscillating electromagnetic waves, which can be grabbed by a nanoantenna and further rectified by a diode into useful energy. This combination of nanoantenna and diode is known as 'Rectenna system.' Multilayer insulator diodes, which operate on the principle of electron tunneling, are one of the few candidates for such high-frequency operation. In this article, different combinations of the metal-insulator-insulator-metal (MII1I2M2) diode are studied for operation at high frequency (28.3 THz or 10.6 mu m). The thickness of varying insulator layers with different dielectric constants is simulated and optimized to have the best resistor-capacitor time constant matching and an enhanced rectification. To the best of our knowledge, this is the first comprehensive and systematic study of the MII1I2M2 diode-based rectenna system for energy harvesting applications at 28.3 THz.