News Researchers tip reversed LEDs for cooling breakthrough

This works because basic physics (as long as LED generates some current, it is "soaking" up photon energy from its surroundings, thereby cooling them). As long as energy absorbed is moved (and dissipated) somewhere else this provides localized cooling effect.

But here's a thing: one can move even more energy using phase-change in refrigerant. I don't think my AC has 1 sq. meter evaporator, yet it can pump kilowatts worth of energy continuously.

 

FInally a use for RGB???

 

By the time this scales up to pumping 3.5 kilowatts of energy from hot side to cold side it's not the size of grain of rice either. The hypothetical figure they are hoping for at some point in the (distant?) future is 1 kilowatt per square meter, provided that tehy somehow figure out a production process that allows for that sub 10 nanometer spacing.while simultaneously depositing over extremely large area (far in excess of semiconductor wafers in use these days) ...

Chances are that a LED layer introduces enough thermal resistance for all the benefits of such cooling to be offset by it and that a simple finned heatsink with perfect mirror-polished sub 10 nanometer gap would be able to dissipate more heat per area.