Lemaire Baptiste, Yu Yanhao, Molinari Nicola, Wu Haichao, Goodwin Zachary A H, Stricker Friedrich, Kozinsky Boris, Aizenberg Joanna
John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138.
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138.
Proc Natl Acad Sci U S A. 2023 Aug 22;120(34):e2308804120. doi: 10.1073/pnas.2308804120. Epub 2023 Aug 14.
The next-generation semiconductors and devices, such as halide perovskites and flexible electronics, are extremely sensitive to water, thus demanding highly effective protection that not only seals out water in all forms (vapor, droplet, and ice), but simultaneously provides mechanical flexibility, durability, transparency, and self-cleaning. Although various solid-state encapsulation methods have been developed, no strategy is available that can fully meet all the above requirements. Here, we report a bioinspired liquid-based encapsulation strategy that offers protection from water without sacrificing the operational properties of the encapsulated materials. Using halide perovskite as a model system, we show that damage to the perovskite from exposure to water is drastically reduced when it is coated by a polymer matrix with infused hydrophobic oil. With a combination of experimental and simulation studies, we elucidated the fundamental transport mechanisms of ultralow water transmission rate that stem from the ability of the infused liquid to fill-in and reduce defects in the coating layer, thus eliminating the low-energy diffusion pathways, and to cause water molecules to diffuse as clusters, which act together as an excellent water permeation barrier. Importantly, the presence of the liquid, as the central component in this encapsulation method provides a unique possibility of reversing the water transport direction; therefore, the lifetime of enclosed water-sensitive materials could be significantly extended via replenishing the hydrophobic oils regularly. We show that the liquid encapsulation platform presented here has high potential in providing not only water protection of the functional device but also flexibility, optical transparency, and self-healing of the coating layer, which are critical for a variety of applications, such as in perovskite solar cells and bioelectronics.
下一代半导体和器件，如卤化物钙钛矿和柔性电子产品，对水极其敏感，因此需要高效的保护措施，不仅要隔绝各种形式的水（蒸汽、水滴和冰），还要同时具备机械柔韧性、耐久性、透明度和自清洁能力。尽管已经开发出各种固态封装方法，但尚无一种策略能够完全满足上述所有要求。在此，我们报告一种受生物启发的基于液体的封装策略，该策略在不牺牲被封装材料操作性能的情况下提供防水保护。以卤化物钙钛矿为模型系统，我们表明，当用注入疏水油的聚合物基质涂覆钙钛矿时，其因接触水而受到的损害会大幅降低。通过实验和模拟研究相结合，我们阐明了超低水传输速率的基本传输机制，这源于注入液体填充并减少涂层缺陷的能力，从而消除低能量扩散途径，并使水分子以簇的形式扩散，共同构成出色的水渗透屏障。重要的是，作为这种封装方法核心成分的液体的存在提供了一种独特的可能性，即可以逆转水的传输方向；因此，通过定期补充疏水油，可以显著延长封闭的对水敏感材料的寿命。我们表明，本文提出的液体封装平台不仅在为功能器件提供防水保护方面具有很高潜力，而且在涂层的柔韧性、光学透明度和自修复方面也具有很高潜力，这些对于诸如钙钛矿太阳能电池和生物电子学等各种应用至关重要。
