The poor stability of organic-inorganic perovskite solar cells (PSCs) is commonly ascribed to elevated ion migration due to the low electronegativity of iodine. To address this issue, boric acid (BA) was chosen as a stabilizer for perovskite thin films. As a Lewis acid, the boric acid has an sp2 hybridized boron atom, which can readily accept a pair of electrons from the iodine ion in its vacant unhybridized p orbital, and the formation of the Pb-O bond further increases the iodide migration barrier. The significantly increased barrier of the iodine ion migration was demonstrated by the improved phase stability of the perovskite film under an electric field and the obviously enhanced stability of the perovskite films under strong ultraviolet light. The inclusion of the BA stabilizer in PSCs resulted in an enhanced power conversion efficiency (PCE) of 25.52 %. The initial efficiency of the BA-modified device was remained at 80 % after 1000 hours at 85 ℃ under around 30 % relative humidity (RH). When subjected to maximum power point tracking and 20–25 % RH, the PCE of BA-modified devices maintained an initial efficiency of 80 % after 1500 hours.

中文翻译：

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迈向高效稳定的钙钛矿太阳能电池：利用无机硼酸稳定剂抑制离子迁移


有机-无机钙钛矿太阳能电池 （PSC） 稳定性差通常归因于碘的低电负性导致离子迁移增加。为了解决这个问题，硼酸 （BA） 被选为钙钛矿薄膜的稳定剂。作为路易斯酸，硼酸具有一个 sp2 杂化硼原子，可以很容易地接受来自其空的未杂化 p 轨道中的碘离子的一对电子，Pb-O 键的形成进一步增加了碘化物迁移势垒。钙钛矿薄膜在电场下相位稳定性的提高和钙钛矿薄膜在强紫外光下稳定性的明显增强证明了碘离子迁移的势垒显着增加。在 PSC 中加入 BA 稳定剂后，功率转换效率 （PCE） 提高了 25.52 %。BA 改性装置在 85 °C 下、相对湿度 （RH） 约为 30% 的情况下，1000 小时后的初始效率保持在 80%。当受到最大功率点跟踪和 20-25% RH 时，BA 改性器件的 PCE 在 1500 小时后保持 80% 的初始效率。