Wei Li’s research interest is focused on the intersection of photonics and thermal science, aimed at realizing new integrated optoelectronic devices, as well as efficient energy harvesting and conservation.
He proposed and fabricated a type of “metasurface” that is only a few hundred nanometers thick with broken mirror symmetry. Based on this structure he developed the world’s first integrated detector for circularly polarized light and further removed the bottleneck for efficiency improvement of the hot-electron-based integrated photodetectors.
By manipulating the interaction between light and heat at the nanoscale, Dr. Li made many pioneering and groundbreaking contributions to thermal radiation control and radiative cooling. By designing photonic structures that can control thermal radiation and metamerism, he demonstrated radiative cooling and heating films with the same color but a temperature difference of 47°C. He and his collaborators resolved key technological problems in the scalable fabrication of daytime radiative cooling materials, and further developed wearable daytime radiative cooling textiles.
By using the thermodynamic properties of radiative cooling, Dr. Li and collaborators achieved a nighttime power-generating system in which the low temperature of outer space serves as the cold source. They further developed a theoretical framework to show that a series of energy harvesting systems can be designed to simultaneously use the sun and outer space, with thermodynamic efficiency significantly larger than the existing theoretical limits.
Wei Li is now leading an international research team to build a comprehensive research framework of “photonic energy manipulation, harvesting, and applications” to address key challenges in energy and information technologies.