And another headline from the Dept. of Sensationally Miss-Represented Scientific Results.
Vs. reality - the ">100%" is at nano-power levels, and is powered by the LED's temperature falling.
So, while the underlying effect might have some practical application, this is ">100% efficiency" in the same sense that "turned off the LED's electric power, set it on fire, then measured the fire's light output" is ">100% efficiency".