ペロブスカイト太陽電池における効率的な界面層としての制御された接続性を持つ精密調整されたカルバゾールベースポリマー

The strategic molecular design of interfacial layers presents a critical pathway to mitigate losses in perovskite photovoltaics. Here, we engineer two carbazole-based polymers with distinct connectivity patterns, 3,6-3,6-Cbz and 3,6-2,7-Cbz, to systematically investigate molecular connectivity-dependent interfacial phenomena in planar n-i-p PSCs. Comprehensive structure-property analyses reveal that the 3,6-2,7-Cbz architecture enables exceptional π-electron delocalization and optimal energy level alignment, simultaneously achieving (i) superior perovskite surface defect passivation and (ii) interfacial recombination suppression. When implemented as an interfacial modifier, the 3,6-2,7-Cbz polymer delivers a champion device efficiency of 24.16% (V_oc = 1.16 V, J_sc = 25.60 mA/cm², FF = 80.86%) with Spiro-OMeTAD as the HTL representing a significant improvement over both the control (22.61%) and 3,6-3,6-Cbz analogue (22.58%). Strikingly, this approach maintains high performance (23.17% PCE) even with undoped carbazole HTLs (Cz-Pyr), demonstrating remarkable versatility. Through correlated XPS and SCLC characterization, we establish clear structure-performance relationships between polymer connectivity and charge transport dynamics. This work provides fundamental insights into molecular topology engineering for advanced interfacial materials in next-generation photovoltaics.