Passivation of iodine vacancies of perovskite films by reducing iodine to triiodide anions for high-performance photovoltaics
Passivation of iodine vacancies of perovskite films by reducing iodine to triiodide anions for high-performance photovoltaics
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DOI：
10.1016/j.cej.2022.135647
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发表时间：
2022-06
影响因子：
15.1
通讯作者：
Y. Qi;K. Green;Guorong Ma;Surabhi Jha;Kristine Gollinger;Chen Wang;X. Gu;Derek L. Patton;S. Morgan;Qilin Dai
中科院分区：
文献类型：
--
作者：
Y. Qi;K. Green;Guorong Ma;Surabhi Jha;Kristine Gollinger;Chen Wang;X. Gu;Derek L. Patton;S. Morgan;Qilin Dai
倒置钙钛矿太阳能电池(PSCs)与普通PSCs相比，具有制造温度低、成本低等优点，在大规模生产中显示出巨大的潜力。然而，钙钛矿型薄膜的表面缺陷和晶界缺陷，如碘空位，导致效率低、稳定性差。在这里，我们报告了一种用四丁基氯化铵(TABCl)原位钝化缺陷的策略。钙钛矿薄膜生长后，表面缺陷和GB缺陷都被钝化。此外，TABCl通过将I2还原为碘离子来修饰碘空位，从而减少了薄膜中的电荷复合，提高了器件的性能。通过对Tbacl的修饰，器件的功率转换效率(PCE)从18.52%提高到20.36%，同时降低了PSC的VOC损耗。同时，由于TBACl减少了缺陷，因此提高了被连续紫外光照射测试的器件的紫外光稳定性。在连续紫外光照射450min的条件下，PSCs可保持90%以上的PCE。这项工作不仅提供了一种有效钝化包括表面缺陷和GB缺陷在内的原位缺陷的方法，而且还展示了一种通过TBACl的还原能力来修饰碘空位的新策略。此外，TBACl的可还原性抑制了钙钛矿膜的降解，从而提高了稳定性。
Inverted perovskite solar cells (PSCs) exhibit great potential in large-scale fabrication due to the low-temperature manufacturing process and low cost compared to normal PSCs. However, defects at the surface and grain boundaries (GBs) of perovskite films, such as iodine vacancies, lead to low efficiency and poor stability. Herein, we report a strategy to passivate the defects in situ with tetrabutylammonium chloride (TABCl). Both the surface defects and GB defects are passivated after perovskite film growth. Moreover, TABCl modifies iodine vacancies by reducing I2to iodide ions, leading to a decrease in charge recombination in the films and enhanced device performance. The power conversion efficiency (PCE) of devices increases from 18.52% to 20.36 % by TBACl modification, and TBACl also reduces the Voc loss in the PSCs. Meanwhile, TBACl enhances the UV light stability of devices tested by continuous UV light irradiation due to the decreased defects by TBACl. The PSCs could maintain over 90% PCE under continuous UV light irradiation for 450 min. This work not only presents a method to effectively passivate the defects in situ including the surface defects and GB defects but also demonstrates a novel strategy to modify the iodine vacancies by the reducibility of TBACl. In addition, the reducibility of TBACl suppresses the degradation of perovskite films, leading to improved stability.