The ever-more-humble carbon nanotube could also be just the device to make solar panels—and anything that loses energy by way of heat—much more efficient. Rice University scientists are creating arrays of aligned single-wall carbon nanotubes to channel mid-infrared radiation and significantly raise the efficiency of solar energy systems.
The invention rests on another by Kono’s group in 2016 when it discovered an easy method to create highly aligned, wafer-scale films of closely packed nanotubes. Conversations with Naik, who joined Rice in 2016, led the pair to see if the films might be used to lead thermal photons. Thermal photons are just photons emitted from a hot body.
Infrared radiation is an element of sunlight that delivers heat to the planet, but it surely’s solely a small a part of the electromagnetic spectrum. Any hot surface emits light as thermal radiation. The problem is that thermal radiation is broadband, whereas the conversion of sunshine to electricity is efficient provided that the emission is in a narrow band.
The nanotube films presented an opportunity to isolate mid-infrared photons that might otherwise be wasted. “That is the motivation,” Naik stated. “A research by (co-lead writer and Rice graduate student) Chloe Doiron discovered that about 20% of our industrial energy consumption is waste heat. That is about three years of electricity only for the state of Texas. That is lots of energy being wasted.