An external electric field (EEF) was applied to regulate perovskite crystal growth in order to achieve the preferred crystallization. The out-of-plane and in-plane crystallization of MAPbI 3-x Cl x , MAPbI 3 and Cs 0.05 (FA 0.83 MA 0.17 ) 0.95 Pb(I 0.83 Br 0.17 ) 3 perovskites was compared based on the grazing incidence X-ray diffraction technique. The results showed that vertical EEF stretches the perovskite crystals, making them exhibit vertical preferential growth on the substrate while shortening the lateral stacking spacing. Although the upward and downward EEF directions showed a similar regulatory effect on crystallization, they exhibited opposing effects on the built-in field in a photovoltaic device. This work reveals the mechanism of perovskite crystal stacking under an external field.

中文翻译：

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电场控制的晶体堆叠，可生产高质量的有机-无机卤化物钙钛矿

施加外部电场（EEF）调节钙钛矿晶体的生长，以实现最佳的结晶效果。根据掠入射X射线比较了MAPbI 3-x Cl x，MAPbI 3和Cs 0.05（FA 0.83 MA 0.17）0.95 Pb（I 0.83 Br 0.17）3钙钛矿的面外和面内结晶衍射技术。结果表明，垂直EEF拉伸钙钛矿晶体，使它们在基底上表现出垂直优先生长，同时缩短了横向堆叠间距。尽管向上和向下的EEF方向对结晶显示出相似的调节效果，但它们对光伏设备的内置场却显示出相反的效果。这项工作揭示了在外部场下钙钛矿晶体堆叠的机理。