Biomineral-inspired mechanically tough perovskite solar cells with enhanced stability

钙钛矿太阳能电池（PSCs）是溶液可加工的，具有高效率和低成本的可再生电力。不幸的是，psc的广泛应用受到其长期稳定性差的阻碍。他们的竞争对手，晶体硅太阳能电池，提供25年的使用寿命。然而，高效psc的运行稳定性不到6个月。钙钛矿具有非常低的机械韧性，这是因为分离钙钛矿晶体所需的能量本质上很低。太阳能电池的使用寿命随着机械韧性的增加而增加，我们的目标是利用这种关系来大大提高高效PSCs的稳定性。从高韧性的天然生物材料（如珍珠质）中获得灵感，我们将使用合成的粘附蛋白类似物将晶体粘合在一起，并增加钙钛矿的机械韧性。我们的新颗粒是超可变形的纳米级凝胶颗粒（称为超低交联纳米凝胶，ULC纳米凝胶）。在我们早期工作的基础上，传统纳米凝胶提高了铅- psc的稳定性，新型ULC纳米凝胶将被制备成保形涂层并相互连接钙钛矿晶体。它们会变平，变得超薄，并允许电荷在晶体之间不受阻碍地移动。研究无铅、锡钙钛矿，通过提高化学稳定性和机械韧性相结合的方式提高其使用稳定性。机械韧性和PSC稳定性之间的联系将通过实验和使用最先进的建模技术进行研究。建模还将用于研究化学降解所涉及的能量变化，从而建立具有增强稳定性的psc的材料设计规则。如果这个项目取得成功，我们将对钙钛矿的机械韧性和稳定性之间的相互作用有更深入的了解，同时也将获得一个预计使用寿命为8年的高效示范装置。这样的结果将使大规模部署钙钛矿光伏无二氧化碳发电更加接近，并提高能源安全。

Perovskite solar cells (PSCs) are solution processable, have high efficiencies and promise low cost renewable electricity. Unfortunately, the widespread application of PSCs is being held back by their poor long-term stability. Their established rivals, crystalline-silicon solar cells, offer a 25 year operational lifetime. However, high efficiency PSCs are operationally stable for less than 6 months. Perovskites have very low mechanical toughness due to the intrinsically low energy required to separate perovskite crystals. Solar cell operation lifetime increases with mechanical toughness and we aim to exploit this relationship to greatly enhance the stability of high efficiency PSCs. Taking inspiration from highly tough natural biomaterials (such as nacre) we will use synthetic analogues of adhesive proteins to glue the crystals together and increase perovskite mechanical toughness. Our new particles are ultra-deformable nanometre-sized gel particles (termed ultra-low crosslinked nanogels, ULC nanogels). Building on our earlier work where conventional nanogels improved lead-PSC stability, novel ULC nanogels will be prepared that conformally coat and interlink perovskite crystals. They will flatten to become ultra-thin and allow charges to move unhindered between crystals. We will also study lead-free, tin-perovskites and increase their operational stability by a combination of improvements in chemical stability and mechanical toughness. The link between the mechanical toughness and PSC stability will be investigated experimentally and using state-of-the-art modelling techniques. Modelling will also be used to study the energy changes involved in chemical degradation so as to establish materials design rules for PSCs with enhanced stability. A successful outcome to this project would provide improved fundamental understanding of the interplay between perovskite mechanical toughness and stability as well as a high efficiency demonstrator(s) with a projected operation lifetime of 8 years. Such a result would bring the large-scale deployment of perovskite photovoltaics for CO2-free electricity generation closer and increase energy security.