Defect Passivation and Stress Release Strategies for Inverted Perovskite Solar Cells Based on the Low-Pressure-Assisted Solution Process

Perovskite solar cells (PSCs) have attracted much attention in the global photovoltaic field due to their excellent optoelectronic properties. However, the intrinsic crystalline properties and the preparation methods of perovskites result in numerous defects and residual stress in the perovskite film. To address this issue, the additive 3-methylthio-1-propylammonium bromide (3MeSPABr) was added to the perovskite precursor solution, and PSCs with an inverted structure via a low-pressure-assisted solution process were fabricated. The additive was found to interact with the perovskite through strong coordination and hydrogen bonding, passivate defects, and alleviate residual tensile stress. The power conversion efficiency (PCE) of the PSCs as high as 21.99% was obtained. Besides, the addition of 3MeSPABr also increases the hydrophobicity of the perovskite film and improves the stability of the PSCs.