Deterioration tends to be roughly linear on an Arrhenius scale, which is basically the scale which is exponential on the inverse temperature. This is because deterioration tends to be roughly linear on the activation energy of defects.
What that means in practice is that hardly anything happens below a certain temperature, but it goes all to hell in a flash, above that. The "certain temperature" for any particular sample depends on what you consider "a flash".
You would be pretty peeved if your solar panel went all to hell in a year, so you calibrate accordingly.
I guess these could be particularly well suited to colder / less sunny climates. Which could be a very good thing, given that in sunny climates existing technologies are already pretty much good enough.
