Hybrid nanomaterial converts light and heat into electricity
By Darren Quick
November 13, 2012
We’ve seen nanomaterials that can be used to convert light into electricity and others that can convert heat into electricity. Now researchers from the University of Texas at Arlington and Louisana Tech University have created a hybrid nanomaterial that can do both. By pairing the material with microchips, the researchers say it could be used in self-powered sensors, low-power electronic devices, and biomedical implants.
While single-walled carbon nanotubes (SWNTs) have been used in the construction of transparent solar cells and all-carbon solar cells, these are still very inefficient when compared to their conventional photovoltaic brethren. By supplementing the electricity generated by light with some thermoelectricity, the hybrid nanomaterial could outperform materials that only do one or the other.
“If we can convert both light and heat to electricity, the potential is huge for energy production,” said UT Arlington associate physics professor Wei Chen. “By increasing the number of the micro-devices on a chip, this technology might offer a new and efficient platform to complement or even replace current solar cell technology.”
The new material was synthesized by combining copper sulfide nanoparticles and SWNTs and then used in a prototype thermoelectric generator that the team hopes will eventually be able to produce milliwatts of power.
Compared to SWNT thin-film devices, the researchers say the new thin-film structure increases light absorption by as much as 80 percent in laboratory tests, making it a more efficient generator. Additionally, copper sulfide is much cheaper and more readily available than the noble metals used in similar hybrids.
Lab tests also showed that the optical and thermal switching effect exhibited by the hybrid nanomaterial thin-film devices could be enhanced by up to 10 times by using asymmetric light illumination and thermal radiation rather than symmetric illumination.
The team's paper appears in the journal Nanotechnology.
Source: UT Arlington