MIT researchers Parthiban Santhanam, Dodd Joseph Gray, Jr., and Rajeev J. Ram discovered that reducing the amount of energy required to release an electron also reduced the amount of light the LED put out, but only by half as much as the amount of energy being cut.
Reducing the power going to the LED by a factor of four, in other words, reduced the light by a factor of 2.
By reducing the energy level more and more, the MIT crew eventually switched the LED's power use from the norm, in which it uses more energy than it puts out, to the opposite.
Reducing the input power to 30 picowatts left the LED shining with 70 picowatts of light, which really seems as if it should violate the kind of laws that end up in nuclear meltdowns or giant lizards rising from the sea to stomp Tokyo.
Not so, apparently.
As the input power levels come down, electrons looking for a new home also look for alternative sources of energy. Atoms vibrate all the time in a pattern called Brownian Movement; the colder they are the less Brownian Movement there is. The hotter the environment is the more they vibrate.
In the MIT LED bulb, researchers ratchet down the electrical power so that electrons wanting a new home have to use vibrations of the atoms around them to get enough energy to move.
By taking that energy they slow down the vibration of other atoms.
Slowing the vibration makes the whole thing slightly colder.
So, by reducing the power far enough, the MIT researchers discovered how to make an LED use the heat and motion in its own mass of atoms to boost its power far beyond the power that went into lighting them.
LEDs that produce more light than the electricity they use, and cool the room, too
The result is still far too dim to be usable, so it may be years before the hardware store carries light bulbs that actually add energy and eliminate heat from any application in which they're installed.
vibrations of the lattice of atoms making up the surface of the LED contribute the energy of that motion to the effort of electrons to escape, slowing their motion slightly as a result.
Reducing the Brownian Motion within and between atoms makes an object colder whether it should be or not.
The end result is a single LED that puts out far more light than it takes in, but doesn't violate any laws of physics by doing so. Rather than having to get the extra energy from the nether regions, it
Like I said, it sounds like an April Fools joke: a light bulb that gives off more energy in light than it takes in as electricity, and reduces the amount of heat in its immediate area, essentially radiating cold.