Atmospheric influence on negative-illumination photovoltaic effect with terrestrial radiation

Terrestrial radiation—thermal radiation emitted from the Earth's surface into outer space—can be harnessed for electrical power generation using p-n junction diodes. This process, known as the negative-illumination photovoltaic effect, where such radiation results in a negative output, contrasts with conventional solar cells. As a potential carbon-free energy source, this effect offers a promising avenue for sustainable energy generation. The efficiency of power generation from terrestrial radiation is influenced by atmospheric absorption in the infrared wavelength range. In this study, we present the first experimental comparison of negative-illumination photovoltaic power generation with and without atmospheric influence. We observed that the photovoltage of infrared diodes exposed to the open sky under clear conditions is significantly reduced compared to that measured when the diodes face a cold surface cooled by liquid nitrogen. The experimental findings are consistent with the analysis derived from simulations of the atmospheric downward radiation spectrum.