  Context: Polycyclic Aromatic Hydrocarbons, largely known as PAHs, are
widespread in the universe and have been identified in a vast array of
astronomical observations from the interstellar medium to protoplanetary discs.
They are likely to be associated with the chemical history of the universe and
the emergence of life on Earth. However, their abundance on exoplanets remains
unknown.
  Aims: We aim to investigate the feasibility of PAH formation in the
thermalized atmospheres of irradiated and non-irradiated hot Jupiters around
Sun-like stars.
  Methods: To this aim, we introduced PAHs in the 1-D self-consistent forward
modeling code petitCODE. We simulated a large number of planet atmospheres with
different parameters (e.g. carbon to oxygen ratio, metallicity, and effective
planetary temperature) to study PAH formation. By coupling the thermochemical
equilibrium solution from petitCODE with the 1-D radiative transfer code,
petitRADTRANS, we calculated the synthetic transmission and emission spectra
for irradiated and non-irradiated planets, respectively, and explored the role
of PAHs on planet spectra.
  Results: Our models show strong correlations between PAH abundance and the
aforementioned parameters. In thermochemical equilibrium scenarios, an optimal
temperature, elevated carbon to oxygen ratio, and increased metallicity values
are conducive to the formation of PAHs, with the carbon to oxygen ratio having
the largest effect.
