【摘要】 钙钛矿中卤素离子容易扩散穿透电荷传输层并腐蚀金属背电极,任何结构的钙钛矿太阳能电池因此都具有较差的器件稳定性.解决钙钛矿器件长期运行稳定性是实现其未来大规模商业化的关键因素之一.本文采用了一种电子传输侧界面稳定化策略,可以同时大幅提高器件效率和长期稳定性.该策略是在钙钛矿和富勒烯(C₆₀)电子传输层之间引入了一种化学和光学更稳定的有机小分子电子传输材料Cl₆SubPc.它不仅起到了钝化钙钛矿表面的作用,还有效地抑制了卤素离子扩散.使用Cl₆SubPc/C₆₀复合电子传输层的器件可以获得22%的冠军光电转换效率和21.3%第三方认证效率,显著高于C₆₀单层参比器件效率.同时,器件在连续模拟太阳光照的条件下衰减至初始效率90%的时间(T₉₀)达到2034h,暗态氮气氛围下7000h后仍维持初始效率的99%,氮气氛围里加热2000小时后依然保持初始效率的80%.另外,满足ISOS-O-1测试标准的户外稳定性T₉₅达到1272 h,更加严苛的双85稳定性测试T80达到816 h.究其稳定机制,本文采用高分辨透射电子显微镜揭示了界面二维和三维钙钛矿晶粒的晶格近原子像,同时通过其附带的电子能量损失光谱原位成像了碘离子迁移确凿证据.进一步结合X射线光电子能谱、二次离子质谱以及密度泛函计算等手段揭示Cl₆SubPc中硼和氮原子与碘离子结合是阻挡碘离子迁移的关键原因.本文的研究结果将极大推动钙钛矿太阳能电池技术发展,使其技术商业化进程又向前迈进了坚实的一步.更多还原

【Abstract】 Perovskite solar cells（PSCs） commonly exhibit significant performance degradation due to ion migration through the top charge transport layer and ultimately metal electrode corrosion. Here, we demonstrate an interfacial management strategy using a boron chloride subphthalocyanine（Cl₆SubPc）/fullerene electron-transport layer, which not only passivates the interfacial defects in the perovskite, but also suppresses halide diffusion as evidenced by multiple techniques, including visual element mapping by electron energy loss spectroscopy. As a result, we obtain inverted PSCs with an efficiency of 22.0%（21.3%certified）, shelf life of 7000 h, T₈₀ of 816 h under damp heat stress（compared to less than 20 h without Cl₆SubPc）, and initial performance retention of 98% after 2000 h at 80 ℃ in inert environment, 90% after 2034 h of illumination and maximum power point tracking in ambient for encapsulated devices and 95% after 1272 h outdoor testing ISOS-O-1. Our strategy and results pave a new way to move PSCs forward to their potential commercialization solidly.更多还原