Dimensional engineering of interlayer for efficient large-area perovskite solar cells with high stability under ISOS-L-3 aging test.

The utilization of low-dimensional perovskites (LDPs) as interlayers on three-dimensional (3D) perovskites has been regarded as an efficient strategy to enhance the performance of perovskite solar cells. Yet, the formation mechanism of LDPs and their impacts on the device performance remain elusive. Herein, we use dimensional engineering to facilitate the controllable growth of 1D and 2D structures on 3D perovskites. The differences of isomeric ligands in electrostatic potential distribution and steric effects for intermolecular forces contribute to different LDPs. The 1D structure facilitates charge transfer with favored channel orientation and energy level alignment. This approach enables perovskite solar modules (PSMs) using 2,2',7,7'-tetrakis[,-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene to achieve an efficiency of 20.20% over 10 by 10 square centimeters (cm) and 22.05% over 6 by 6 cm. In particular, a PSM (6 by 6 cm) using poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] maintains an initial efficiency of ~95% after 1000 hours under the rigorous ISOS-L-3 accelerated aging tests, marking a record for the highest stability of n-i-p structure modules.