New tech breakthough will allow drones to fly for days

Prof. Eli Yablonovitch is the co-author of a paper published in the Proceedings of the National Academy of Sciences (PNAS) that describes a groundbreaking discovery which has allowed researchers to raise the efficiency of thermophotovoltaics from 23% (where it has stayed for 15 years) to an unprecedented 29%. This ultralight alternative power source could allow drones and other unmanned aerial vehicles to operate continuously for days.  The paper, "Ultraefficient thermophotovoltaic power conversion by band-edge spectral filtering," co-authored by a 10-person research team that includes postdoc Luis Pazos-Outon, details how a highly reflective mirror installed on the back of a photovoltaic cell can reflect low energy infrared photons to reheat the thermal source, providing a second chance for a high-energy photon to be created and generate electricity.