Aminosulfonate-Modified Buried Interface Coordination-Induced Defect Dassivation and Strain Relief toward Efficient Perovskite Solar Cells

Continuous breakthroughs in the photovoltaic performance of perovskite solar cells (PSCs) have demonstrated the enormous potential for commercial application. However, accumulating numerous defects at the buried interface and residual stresses in the perovskite film severely restrict the further improvement of photovoltaic conversion efficiency (PCE) and device stability. Herein, an environmentally friendly and economical sodium sulfamate (SS) was employed as a versatile buried interface modifier to achieve simultaneous interface defect passivation, regulation of energy levels, and residual stress regulation through the synergistic effects among various functional groups. As a result, the average PCE of the optimized PSC increased from 23.02% to 24.83%, along with the champion efficiency of 25.07%. Meanwhile, the unencapsulated optimized device can still retain 80% of its initial PCE after 1048 h of continuous operation, which was significantly higher than the 36.50% of the controlled device. This work provides valuable insights for further leveraging interfacial modification strategies to achieve multifunctionality and break through the photovoltaic performance of PSCs.