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摘要
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In this study, the amphiphilic molecule octyltrimethylammonium bromide (OTAB) was integrated into 3D triple-cation lead mixed-halide (CsFAMA) perovskite films, forming a self-assembled layer on the perovskite surface. This modification significantly enhanced water resistance and elevated the energy band levels by forming an interfacial dipole, which effectively reduced carrier reverse recombination by blocking the diffusion of photogenerated electrons. OTAB also improved surface smoothness, film uniformity, and promoted a face-on crystal orientation. Additionally, the bromide ions in OTAB effectively passivated defects, thereby suppressing ion migration and mitigating non-radiative recombination. As a result, OTAB-based devices exhibited remarkable performance, achieving a power conversion efficiency (PCE) of 22.61 %, with a short-circuit current density (Jsc) of 25.36 mA/cm2, an open-circuit voltage (Voc) of 1.10 V, and a fill factor (FF) of 81.36 %. These devices also demonstrated exceptional stability, retaining 100 % of their initial PCE after 3312 h under 50 % relative humidity at 25 °C, and maintaining 80 % of their original efficiency (T80 lifetime) after 2160 h at 65 °C and 1310 h at 85 °C in a nitrogen atmosphere. The successful incorporation of this amphiphilic molecule paves the way for significant advancements in photovoltaic technology. |