With the development of nanotechnology, researchers using nanowires in solar cells are finding that solar cell efficiency limits may be higher than they previously thought possible.
Current commercial silicon-based solar cell efficiency is less than 15%, which means that more than 85% of the sun’s energy is lost to heat and reflection. Modern theory places silicon-bases solar cell efficiency limits around 50%, but recent developments in nanotechnology have been pushing that theoretical limit upward.
Researchers at Lund University believe that, once they get the process down, they could realize a 100% efficient solar cell. A 100% efficient solar cell would definitely push the boundaries of solar cell efficiency.
Solar cells incorporating nanotechnology would naturally be more efficient. Nanowires resonate at the wavelength of the light they absorb, which is directly related to their length. A nanowire of the correct length exposed to its resonant wavelength of light concentrates the sun’s rays by a factor of fifteen.
This doesn’t mean that we can have a solar cell efficiency of 750%, but it does mean that we could be edging close to 100% efficiency. Nanowires of different lengths, all responding to different wavelengths of light, could theoretically convert every part of the visible, and invisible, spectrum into electricity. Nanowire solar cells could get smaller and generate more power, depending on the application.
Image©Niels Bohr Institute