Abstract: The present invention aims to provide a flexible solar cell having excellent high-temperature, high-humidity durability and excellent initial performance. The present invention relates to a flexible solar cell including, on a flexible substrate: an electrode; a transparent electrode; and a photoelectric conversion layer disposed between the electrode and the transparent electrode, the photoelectric conversion layer containing an organic-inorganic perovskite compound, the flexible substrate including an aluminum foil and an aluminum oxide film formed on the aluminum foil, the flexible substrate having a ratio of the thickness of the aluminum oxide film to the total thickness of the aluminum foil and the aluminum oxide film of 0.1% or higher and 15% or lower.

Abstract: The present invention aims to provide a solar cell having high durability against deterioration due to moisture ingress from the side surfaces. The solar cell 10 of the present invention includes: first and second electrodes 12 and 17; a perovskite layer 14 provided between the first and second electrodes 12 and 17 and containing an organic-inorganic perovskite compound (A) represented by the formula RMX3 where R is an organic molecule, M is a metal atom, and X is a halogen atom; and a side-surface-protecting layer 15 provided on a peripheral side of the perovskite layer 14 to coat at least part of a side surface of the perovskite layer 14, the side-surface-protecting layer 15 containing at least one selected from the group consisting of a metal halide (B1) and an organometal halide (B2) or containing an organohalide (C).

Abstract: The present invention aims to provide a solar cell having high photoelectric conversion efficiency that is less likely to decrease even under application of a voltage for a long period of time. Provided is a solar cell including: a cathode; a photoelectric conversion layer; and an anode in the stated order, the photoelectric conversion layer including an organic-inorganic perovskite compound represented by the formula: R-M-X3 wherein R represents an organic molecule, M represents a metal atom, and X represents a halogen or chalcogen atom, the solar cell further including, between the photoelectric conversion layer and the anode layer, a diffusion prevention layer including at least one selected from the group consisting of: metal oxides, metal nitrides, and metal oxynitrides each containing a group 6 to 15 metal in the periodic table; and carbon.