This once again has me wondering about quantum dots - wondering if quantum dots can be used for refrigeration (there're papers as far back as '93).

I figured they'd have to be infrared, and then I got distracted by the difficulties producing dots that large[1].

It seems that there's been some trouble scaling up to that scale (though scaling down into the UV would be even more problematic).

[1] - https://www.osti.gov/servlets/purl/1500079