biostudies-literatureKot MBundesministerium für Wirtschaft und KlimaschutzNarodowe Centrum Badań i Rozwojue2412711https://www.ebi.ac.uk/biostudies/studies/S-EPMC12021027biostudies-literatureUnknown12(16)Dark and light current-voltage characteristics of perovskite solar absorbers are analyzed in terms of their carrier densities. The analysis reveals p-type large polarons as a dominant carrier type in the investigated perovskite solar cells. The mechanism causing photosensitivity is attributed to the dissociation (and pairing) of bipolarons to large polarons (and vice versa) that are controlled by the internal potential Γ. As an example, the polaron concept is tested for a formamidinium lead triiodide perovskite solar cell. The individual steps of the data analysis are demonstrated and determine the ionicity factor of this perovskite film, quantify the density of the large polarons, and predict the gain and loss of photo-induced carriers. It is deduced that a reversible light-on/off operatiAdvanced science (Weinheim, Baden-Wurttemberg, Germany)Photosensitivity and Carrier Densities of Perovskite Solar Absorbers.PMC12021027NOR/SGS/DMOPV/0190/2020‐00NOR/SGS/DMOPV/0190/2020-00KK5087602BR1Gawlinska-Necek KSchmeißer DPozarowska EKot MHenkel KfalsePhotosensitivity and Carrier Densities of Perovskite Solar Absorbers.Dark and light current-voltage characteristics of perovskite solar absorbers are analyzed in terms of their carrier densities. The analysis reveals p-type large polarons as a dominant carrier type in the investigated perovskite solar cells. The mechanism causing photosensitivity is attributed to the dissociation (and pairing) of bipolarons to large polarons (and vice versa) that are controlled by the internal potential Γ. As an example, the polaron concept is tested for a formamidinium lead triiodide perovskite solar cell. The individual steps of the data analysis are demonstrated and determine the ionicity factor of this perovskite film, quantify the density of the large polarons, and predict the gain and loss of photo-induced carriers. It is deduced that a reversible light-on/off operati2025-01-01T00:00:00Z2025 Apr2025-07-01T03:05:44.414Z2025-07-01T03:05:44.414ZS-EPMC120210273999649110.1002/advs.202412711