Abstract:
In the pursuit of highly efficient perovskite solar cells, spiro-OMeTAD has demonstrated recorded power conversion efficiencies (PCEs), however, the stability issue remains one of the bottlenecks constraining its commercial development. In this study, we successfully synthesize a novel self-polymerized spiro-type interfacial molecule, termed v-spiro. The linearly arranged molecule exhibits stronger intermolecular interactions and higher intrinsic hole mobility compared to spiro-OMeTAD. Importantly, the vinyl groups in v-spiro enable in situ polymerization, forming a polymeric protective layer on the perovskite film surface, which proves highly effective in suppressing moisture degradation and ion migration. Utilizing these advantages, poly-v-spiro-based device achieves an outstanding efficiency of 24.54 %, with an enhanced open-circuit voltage of 1.173 V and a fill factor of 81.11 %, owing to the reduced defect density, energy level alignment and efficient interfacial hole extraction. Furthermore, the operational stability of unencapsulated devices is significantly enhanced, maintaining initial efficiencies above 90 % even after 2000 hours under approximately 60 % humidity or 1250 hours under continuous AM 1.5G sunlight exposure. This work presents a comprehensive approach to achieving both high efficiency and long-term stability in PSCs through innovative interfacial design.
摘要:
为了追求高效的钙钛矿太阳能电池,spiro-OMeTAD已经证明了创纪录的功率转换效率(PCE),然而,稳定问题仍然是制约其商业发展的瓶颈之一。在这项研究中,我们成功合成了一种新型的自聚合螺型界面分子,被称为v-spiro。与螺-OMeTAD相比,线性排列的分子表现出较强的分子间相互作用和较高的固有空穴迁移率。重要的是,v-spiro中的乙烯基能够原位聚合,在钙钛矿薄膜表面形成聚合物保护层,这证明在抑制水分降解和离子迁移方面非常有效。利用这些优势,聚-v-spiro基器件实现了24.54%的突出效率,具有1.173V的增强开路电压和81.11%的填充因子,由于缺陷密度降低,能级对齐和高效的界面孔提取。此外,未封装器件的运行稳定性显著增强,即使在约60%湿度下2000小时或在连续AM1.5G阳光照射下1250小时后,初始效率仍保持在90%以上。这项工作提出了一种全面的方法,通过创新的界面设计在PSC中实现高效率和长期稳定性。