Average charge per grain (upper left) and its fractional contribution to the total charge (upper right). The location of the transition from ionized to neutral carbon is overplotted in the upper panels. The contribution of the positively charged PAHs (PAH⁺, PAH⁺⁺, and PAH⁺⁺⁺) is shown in the lower left panel, while the contribution of the negatively charged PAHs (PAH⁻) is shown in the lower right panel. The contours show the extinction and the location in the disk where the abundance of gas phase and frozen PAHs are equal. The model is the DIANA typical disk with β_mid = 10⁴. Silicate dust grains remains at T_dust < 1500 K at all disk heights (see Fig. F.1).