State Key Laboratory of Silicon Materials, MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science & Engineering, Zhejiang University , Hangzhou 310027, China.
J Am Chem Soc. 2015 Feb 25;137(7):2674-9. doi: 10.1021/ja512518r. Epub 2015 Feb 13.
Morphology control is critical to achieve high efficiency CH3NH3PbI3 perovskite solar cells (PSC). The surface properties of the substrates on which crystalline perovskite thin films form are expected to affect greatly the crystallization and, thus, the resulting morphology. However, this topic is seldom examined in PSC. Here we developed a facile but efficient method of modifying the ZnO-coated substrates with 3-aminopropanioc acid (C3-SAM) to direct the crystalline evolution and achieve the optimal morphology of CH3NH3PbI3 perovskite film. With incorporation of the C3-SAM, highly crystalline CH3NH3PbI3 films were formed with reduced pin-holes and trap states density. In addition, the work function of the cathode was better aligned with the conduction band minimum of perovskite for efficient charge extraction and electronic coupling. As a result, the PSC performance remarkably increased from 9.81(±0.99)% (best 11.96%) to 14.25(±0.61)% (best 15.67%). We stress the importance of morphology control through substrate surface modification to obtain the optimal morphology and device performance of PSC, which should generate an impact on developing highly efficient PSC and future commercialization.
形态控制对于实现高效率 CH3NH3PbI3 钙钛矿太阳能电池（PSC）至关重要。结晶钙钛矿薄膜形成的衬底的表面特性预计会极大地影响结晶过程，从而影响最终的形态。然而，这个主题在 PSC 中很少被研究。在这里，我们开发了一种简便但有效的方法，用 3-氨基丙酸钠（C3-SAM）修饰 ZnO 涂层衬底，以引导结晶演化，实现 CH3NH3PbI3 钙钛矿薄膜的最佳形态。通过引入 C3-SAM，形成了具有更少针孔和更少陷阱态密度的高结晶性 CH3NH3PbI3 薄膜。此外，阴极的功函数与钙钛矿的导带最小值更好地匹配，从而实现了高效的电荷提取和电子耦合。结果，PSC 的性能显著提高，从 9.81(±0.99)%（最佳 11.96%）提高到 14.25(±0.61)%（最佳 15.67%）。我们强调通过衬底表面修饰进行形态控制的重要性，以获得 PSC 的最佳形态和器件性能，这将对开发高效 PSC 和未来的商业化产生影响。
