Recently, perovskite nanocomposites have attracted much attention as active layers due to the relatively high stable efficiency of solar cells based on them. In this paper, we study perovskite nanocomposite layers based on semiconductive/nonconductive molecules or polymers, their deposition methods, properties, and influence on the device performance. We have found that the quality of the perovskite layer (morphology and crystallinity, cross-linked grains, trap states density, as well as conductivity and charge carrier mobility) is strongly affected by various factors related to the additive: such as type (i. e. semiconductive or nonconductive, molecule or polymer), chemical structure (backbone length and molecular weight, functional groups, π system, side chains, donating atoms and basicity), amount, solubility, conductivity, photoactivity, polarity, hydrophobicity, and addition methods. Due to the small amounts added, these additives can lead to slight changes in energy levels, bandgap (Eg), and light absorption properties. Ultimately, using the suitable deposition method and additive at an optimal amount can greatly improve the stability and efficiency of the devices and reduce hysteresis.
