Characteristics of Perovskite Solar Cells under Low-Illuminance Conditions

Organic–inorganic perovskite solar cells have attracted much attention as high performance and low-cost photovoltaic devices. Because it consists of p-type hole transport layer, perovskite layer, and n-type electron transport layer similar to a p–i–n structure, it works effectively even under low-illuminance conditions, such as indoor lighting. In this work, we focused on the characteristics of perovskite solar cells under low-illuminance conditions, and a detailed investigation was carried out. The open-circuit voltage yielded at around 70% of AM1.5 at 0.1 mW/cm2 illuminance, which is similar to that under indoor lighting. From impedance spectroscopy, it was suggested that the planar-type structure solar cell provided better resistance characteristics than that of the mesostructured cell for indoor applications. Comparing the characteristics of these types of solar cells, planar-type solar cells show higher voltage than mesostructured cells under low-illuminance conditions. These results have shown important implications for various applications of perovskite solar cells.