Development of 3D/2D Perovskite Solar Cells using a Spray-based Sequential Deposition

The 3D-perovskite halides have gained a considerable reputation as solar absorbers versus their counterpart semiconductor materials since they achieved a remarkably high-power conversion efficiency of 25.2% within a decade. However, lattice degradation and sensitivity against moisture, oxygen, and strong irradiation still hinder perovskite solar cells mass production and commercialization. Herein, we report a new sequential spray deposition method to deposit bulky organic cations (BOCs) on top of the 3D perovskite layer toward forming a protective 3D/2D layer. With controlled thickness and composition, this layer protects the perovskite grains from moisture penetration. The formation of the 2D layer was confirmed by X-ray diffraction, scanning electron microscopy, atomic force microscopy, photoluminescence, and absorption spectroscopy measurements.