Udalova Natalia N, Tutantsev Andrey S, Chen Qi, Kraskov Anastasia, Goodilin Eugene A, Tarasov Alexey B
Laboratory of New Materials for Solar Energetics, Department of Materials Science, Lomonosov Moscow State University, Lenin Hills, 119991 Moscow, Russia.
Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China.
ACS Appl Mater Interfaces. 2020 Mar 18;12(11):12755-12762. doi: 10.1021/acsami.9b21689. Epub 2020 Mar 6.
We found that laser irradiation, being widely used in perovskite photovoltaics for both laser scribing and materials characterization, inevitably causes a cascade of complex photo- and thermochemical conjugated reactions, material melting, and ablation with deep morphological and composition changes of perovskite thin films over a much larger area compared to the initial laser spot. A crucial issue in the advancing or suppression of these degradation processes is related to the origin of the surrounding atmosphere. In particular, an effective approach utilizing an inert gas flow directed onto the exposed area is suggested for the first time to eliminate the negative consequences of perovskite laser scribing. This finding is naturally related to experimental observations of spreading the volatile decomposition products, including elemental iodine, over the pristine perovskite material, regardless of its composition, followed by laser-induced formation of liquid polyiodides. Suppression of decomposition product amount by proper selection of the gas atmosphere and power regime of the laser treatment is of interest to enhance the scribing procedure.
我们发现，激光辐照在钙钛矿光伏领域广泛应用于激光划刻和材料表征，不可避免地会引发一系列复杂的光化学和热化学共轭反应、材料熔化以及烧蚀，导致钙钛矿薄膜在比初始激光光斑大得多的区域出现深度形态和成分变化。这些降解过程的推进或抑制中的一个关键问题与周围气氛的来源有关。特别是，首次提出了一种利用惰性气体流导向暴露区域的有效方法，以消除钙钛矿激光划刻的负面后果。这一发现自然与实验观察结果相关，即挥发性分解产物（包括元素碘）会在原始钙钛矿材料上扩散，无论其成分如何，随后激光诱导形成液态聚碘化物。通过适当选择气体气氛和激光处理的功率模式来抑制分解产物的量，对于改进划刻工艺很有意义。
