> So Raman and electrical engineering professor Shanhui Fan made panels containing layers of silicon dioxide and hafnium oxide on top of a thin layer of silver. These radiate in a unique way: They send heat directly into space, bypassing the Earth’s atmosphere. The panels do this by emitting heat at infrared wavelengths between 8 and 13 micrometers. To these waves, the Earth’s atmosphere is transparent. What’s more, the panels reflect nearly all the sunlight falling on them.
A little further research shows that the atmosphere is opaque at numerous wavelengths and it's probably safe to assume that they intentionally targeted the opaque ones: https://i.imgur.com/eUmTltm.png