Lewis‐Adduct Mediated Grain‐Boundary Functionalization for Efficient Ideal‐Bandgap Perovskite Solar Cells with Superior Stability
Lewis‐Adduct Mediated Grain‐Boundary Functionalization for Efficient Ideal‐Bandgap Perovskite Solar Cells with Superior Stability
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DOI：
10.1002/aenm.201800997
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发表时间：
2018-08
影响因子：
27.8
通讯作者：
Y. Zong;Zhongmin Zhou;Min Chen;N. Padture;Yuanyuan Zhou
中科院分区：
文献类型：
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作者：
Y. Zong;Zhongmin Zhou;Min Chen;N. Padture;Yuanyuan Zhou
最先进的钙钛矿太阳能电池（PSC）的带隙总是大于1.45 eV，这限制了它们理论上可达到的功率转换效率。根据肖克利-奎塞尔极限，带隙为1.2-1.3 eV的新兴混合（Pb，Sn）钙钛矿是单结太阳能电池的理想选择，并且它们有潜力提供更高的效率。然而，这些钙钛矿中Sn（II）的高化学活性使得控制其物理性质和化学稳定性极具挑战性，从而导致PSC具有相对低的PCE和稳定性。在这项工作中，作者将刘易斯-加合物SnF 2·3FACl添加剂用于理想带隙卤化物钙钛矿（IBHP）的溶液加工中，并制备含有具有稳定SnF 2相的连续官能化晶界的均匀大晶粒钙钛矿薄膜。这种富含Sn（II）的晶界网络显著增强了IBHP薄膜的物理性质和化学稳定性。基于这种方法，具有1.3 eV的理想带隙的PSC被制造为具有15.8%的有希望的效率，以及增强的稳定性。本文提出的IBHP中刘易斯加合物介导的晶界功能化的概念指出了在未来稳定的PSC中接近Shockley-Queisser极限的新化学途径。
State‐of‐the‐art perovskite solar cells (PSCs) have bandgaps that are invariably larger than 1.45 eV, which limits their theoretically attainable power conversion efficiency. The emergent mixed‐(Pb, Sn) perovskites with bandgaps of 1.2–1.3 eV are ideal for single‐junction solar cells according to the Shockley–Queisser limit, and they have the potential to deliver higher efficiency. Nevertheless, the high chemical activity of Sn(II) in these perovskites makes it extremely challenging to control their physical properties and chemical stability, thereby leading to PSCs with relatively low PCE and stability. In this work, the authors employ the Lewis‐adduct SnF2·3FACl additive in the solution‐processing of ideal‐bandgap halide perovskites (IBHPs), and prepare uniform large‐grain perovskite thin films containing continuously functionalized grain boundaries with the stable SnF2 phase. Such Sn(II)‐rich grain‐boundary networks significantly enhance the physical properties and chemical stability of the IBHP thin films. Based on this approach, PSCs with an ideal bandgap of 1.3 eV are fabricated with a promising efficiency of 15.8%, as well as enhanced stability. The concept of Lewis‐adduct‐mediated grain‐boundary functionalization in IBHPs presented here points to a new chemical route for approaching the Shockley–Queisser limit in future stable PSCs.