Researchers at the University of Rochester have developed a novel method to boost the performance of solar thermoelectric generators (STEGs), devices that convert heat into electricity, by up to 15 times. The innovation hinges not on improving semiconductor materials, but instead on reengineering the components responsible for heat absorption and dissipation. By using femtosecond laser pulses to etch tungsten into a “black metal,” the researchers greatly enhanced the material’s ability to absorb sunlight while reducing thermal losses. 
They then applied a clever “mini‑greenhouse” effect, overlaying the black metal with a plastic layer to trap heat more efficiently on the hot side. On the cold side, they laser‑nanostructured aluminum to double its cooling performance. Together, these steps substantially increased the temperature differential across the device, dramatically amplifying its electricity output. This improvement could make STEGs a viable power source for compact or off‑grid applications like IoT sensors, wearables, and rural electrification.
