New Material For Solar Thermoelectric Generators

The Debrief reports that "Scientists Turn to ‘Black Metal’ to Make Ultra-Powerful Solar Thermoelectric Generators." From the article:

    Unlike traditional photovoltaic solar panels that convert light into electricity, STEGs convert heat from the sun into power. The technology relies on the transfer of heat energy between a “hot” side and a “cold” side, which can be converted into electricity through a physical phenomenon known as the Seebeck effect. Still, the best STEG only converts around 1% of the solar energy they absorb. For comparison, the best photovoltaic-based residential solar panels on the market can achieve conversion rates exceeding 20%.

    According to Chunlei Guo, a professor of optics and physics and a senior scientist at Rochester’s Laboratory for Laser Energetics, efforts to improve STEG efficiency have focused on semiconductor materials used in their designs. Unfortunately, the researchers note that these efforts have made “modest gains” in overall energy conversion efficiency.

    To develop a STEG that could approach a photovoltaic level of efficiency, the Rochester team took a different approach. In their published study, the researchers explain that they “don’t even touch the semiconductor materials” used in STEGs. Instead, the team said they “focused on the hot and the cold sides of the device” by employing a multi-stage approach.

The article goes on to describe the process, but basically the researchers etched the "hot" and "cold" sides with femtosecond laser pulses to increase the surface area, then covered the "hot" side with a plastic layer to simulate a greenhouse effect. 

Once completed, the team demonstrated their black metal STEG by powering LEDs. Tests of the device’s output showed it generates 15 times more power than previous solar heat energy conversion devices. 

Also:

 Although still in the lab, the team stated that a commercial version of the technology could provide off-grid power to remote and rural locations at a lower material cost compared to photovoltaic panels. Smaller versions of this black metal technology could also power low-demand applications like wireless sensors for the IoT and wearable devices.