Mixed-halide perovskites solar cells through PbICl and PbCl2 precursor films by sequential chemical vapor deposition
Mixed-halide perovskites solar cells through PbICl and PbCl2 precursor films by sequential chemical vapor deposition
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DOI：
10.1016/j.solener.2020.12.042
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发表时间：
2021-02
期刊：
影响因子：
6.7
通讯作者：
S. Ngqoloda;C. Arendse;S. Guha;T. Muller;Stephen C. Klue;S. S. Magubane-S.;C. Oliphant
中科院分区：
文献类型：
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作者：
S. Ngqoloda;C. Arendse;S. Guha;T. Muller;Stephen C. Klue;S. S. Magubane-S.;C. Oliphant
与纯碘基钙钛矿相比，具有氯（Cl）含量的混合卤化物钙钛矿由于更好的电荷传输性质和更长的扩散长度而受到显著关注。Cl掺杂的钙钛矿的上级性质改善了太阳能电池器件性能，尽管钙钛矿膜中Cl组成的定量仍然难以实现。因此，很难将Cl-量与改善的器件性能相关联。在这项工作中，我们通过简单的三步和两步顺序化学气相沉积（CVD）沉积了Cl掺杂的钙钛矿薄膜，其中在工艺的第一步沉积了卤化铅薄膜，随后转化为钙钛矿。没有Cl取代碘被观察到在顺序沉积的氯化铅和碘化铅膜反应，形成氯化碘化铅相（PbICl）。碘离子取代Cl仅发生在向钙钛矿相转化的过程中。与含氯的卤化铅薄膜相比，当将PbI 2薄膜转化为钙钛矿时，实现了大的钙钛矿晶粒（大于2 μm），这与文献相矛盾。然而，与未掺杂的钙钛矿太阳能电池（8.76%）相比，Cl掺杂的钙钛矿太阳能电池显示出高达10.87%的改善的器件效率。
Mixed halide perovskites with chlorine (Cl) content have received significant interest due to better charge transport properties and longer diffusion length compared to pure iodine-based perovskites. The superior properties of Cl-doped perovskites improve solar cell device performance, although the quantification of Cl composition in the perovskite films remain difficult to achieve. Hence, it is difficult to correlate the Cl-quantity with the improved device performance. In this work, we deposited Cl-doped perovskite films through a facile three- and two-step sequential chemical vapor deposition (CVD) where lead halide films were deposited in the first steps of the process and subsequently converted to perovskites. No Cl substitution by iodine was observed during a sequential deposition of lead chloride and lead iodide films which reacted to form a lead chloride iodide phase (PbICl). The substitution of Cl by iodine ions only occurred during the conversion to perovskite phase. Large perovskite grains (greater than 2 µm) were realized when converting a PbI2film to perovskite compared to chlorine containing lead halide films, contradicting literature. However, Cl doped perovskite solar cells showed improved device efficiencies as high as 10.87% compared to an un-doped perovskite solar cell (8.76%).