Improvement of the humidity stability of organic–inorganic perovskite solar cells using ultrathin Al 2 O 3 layers prepared by atomic layer deposition

For the successful commercialization of organic–inorganic halide perovskite solar cells, it is necessary to ensure their stability in addition to high efficiency. In this study, the degradation mechanism of organic–inorganic halide structures in humidity was investigated computationally. Owing to the high polarity of water molecules, the unprotected organic–inorganic structure will inevitably decompose in a humid environment. To improve the ambient stability of the organic–inorganic perovskite solar cells, we introduced an interface modification method using ultrathin compact aluminum oxide (Al 2 O 3 ) layers deposited by atomic layer deposition (ALD). The experimental results showed the ambient stability of the organic–inorganic perovskite solar cell with an ultrathin compact Al 2 O 3 layer was greatly improved without a significant reduction in efficiency.