Effect of air-flow and solvent annealing on fabrication of perovskite active layer and photovoltaic properties of cells with the active layer

Abstract

In perovskite solar cells, the morphology of perovskite active layers is one of important factors for obtaining high energy conversion efficiency (PCE). We investigate the morphology of the crystals and grains of perovskite layer fabricated by a 1-step method incorporated with the air-flow and solvent annealing. Although the crystal and grain sizes of perovskite layer became smaller than the as-grown perovskite layer, the former film quality advanced because of less pinhole. In addition, after the solvent annealing, the crystals and grains of perovskite layer grew promptly in the air-flow treated perovskite layer. The crystal and grain sizes in the air-flow treated perovskite layer were twice larger than those in the as-grown perovskite layer. Finally we fabricated the higher PCE perovskite solar cells by incorporating the air-flow and solvent annealing processes.