  Photochemical hazes are expected to form and significantly contribute to the
chemical and radiative balance of exoplanets with relatively moderate
temperatures, possibly in the habitable zone of their host star. In the
presence of humidity, haze particles might thus serve as cloud condensation
nuclei and trigger the formation of water droplets. In the present work, we are
interested in the chemical impact of such a close interaction between
photochemical hazes and humidity on the organic content composing the hazes and
on the capacity to generate organic molecules with high prebiotic potential.
For this purpose, we explore experimentally the sweet spot by combining
N-dominated super-Earth exoplanets in agreement with Titan's rich organic
photochemistry and humid conditions expected for exoplanets in habitable zones.
A logarithmic increase with time is observed for the relative abundance of
oxygenated species, with O-containing molecules dominating after 1 month only.
The rapidity of the process suggests that the humid evolution of N-rich organic
haze provides an efficient source of molecules with high prebiotic potential.
