AgBiS 2 is a promising and environmentally friendly absorber material for use in hybrid solar cells (HSC). Here, we report a study on the evolution of interfacial phenomena observed during deposition of AgBiS 2 onto mesoporous TiO 2 by the two-stage successive ionic layer adsorption-reaction method. With this approach, inorganic–organic HSC were assembled using Co 2+ doped P3HT as hole transport layer. Surface photovoltage spectroscopy and contact potential difference measurements corroborated a low density of trap states in the ternary chalcogenide and lack of majority carrier barriers, compared to the binary absorbers used as reference. The best HSC exhibits a power conversion efficiency of 2.87% under irradiation of 100 mW cm− 2, which is attractive for an easily scalable, no capping, no passivating synthesis of AgBiS 2.