Enhanced interface adhesion with a polymeric hole transporter enabling high-performance air-processed perovskite solar cells

Strong adhesion between the hole transport layer and transparent conductive oxide is crucial for efficient charge transport and interface stability of inverted perovskite solar cells (PSCs). This study demonstrates a significant improvement in interface adhesion achieved through rational hole transporter design. We design poly-DCPA, a novel polymeric hole transporter exhibiting over four-fold enhancement in adhesion compared to the self-assembled monolayer (SAM) counterpart called DCPA. Poly-DCPA also shows superior conductivity and improved uniformity, enabling blade-coated PSCs fabricated under ambient conditions to achieve a remarkable power conversion efficiency of 24.9%. This surpasses the performance of PSCs using the DCPA SAM as the hole-transporting layer. Furthermore, poly-DCPA-based PSCs exhibit excellent stability, retaining 94% of the initial PCE after over 900 hours of light soaking at 85 degrees C. This work presents a promising strategy for designing hole transporters with enhanced interface adhesion, paving the way for highly efficient and stable PSCs.