Entropic Stabilization of Hybrid Perovskites

杂化钙钛矿的熵稳定

• 批准号: 2852634
• 金额: --
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2852634
• 关键词: Entropic; Stabilization; Hybrid; Perovskites

Hybrid perovskites have revolutionized solar research in the past decade. Materials such as MAPI (CH3NH3PbI3) can act as absorber and is also able to separate charge over large distances, and power conversion efficiencies have risen beyond 20% as a result of this. One of the concerns that has troubled researchers is the degradation of the materials in the presence of water via transfer of the methylammonium proton. Approaches that currently exist to depress these effects include the engineering of PKa of the proton at the A site, as well as the replacement of the organic ion with an inorganic ion e.g. Cs+. However, the materials still show varying amounts of instability. However, recently a new paradigm has emerged that has defied the traditional picture of crystalline solids, which is the notion of high entropy materials.These are very different to traditional materials because they utilise increased disorder to minimise their free energy. In simple terms, this is achieved by adding various elements in equivalent amounts to either the cationic or anionic sublattices in the crystalline state to maximise the entropic mixing term, which in turn minimises the free energy of the solid. There are now a number of materials stabilised in this way including metals, metal oxides and metal sulfides and oxysulfides. In this PhD programme we will test the hypothesis that stabilization can be conferred on hybrid perovskites using this approach. We will make thin films of these new materials by both spin coating and CVD, and test their stability vs water using the latest operando XPS techniques. It is envisaged that a new paradigm for stabilization of hybrid perovskite materials will be established.

在过去的十年中，混合钙壶彻底改变了太阳能研究。诸如MAPI（CH3NH3PBI3）之类的材料可以充当吸收器，并且也能够在大距离内分离电荷，因此功率转换效率提高了20％以上。困扰研究人员的担忧之一是在水存在下通过转移甲基铵质子的降解。目前存在降低这些效果的方法包括A位置上质子的PKA的工程，以及用无机离子（例如CS+。但是，材料仍然显示出不同量的不稳定。但是，最近出现了一种新的范式，它违反了晶体固体的传统图片，这是高熵材料的概念。这些与传统材料非常不同，因为它们利用增加的混乱来最大程度地减少其自由能。简而言之，这是通过在晶体状态中与阳离子或阴离子旋转的各种元素相同的元素来实现的，以最大化熵混合项，从而最大程度地减少了固体的自由能。现在有许多材料以这种方式稳定，包括金属，金属氧化物和金属硫化物和氧气硫化物。在此博士学位课程中，我们将测试可以使用这种方法在混合钙壶赋予稳定化的假设。我们将通过自旋涂层和CVD制作这些新材料的薄膜，并使用最新的Operando XPS技术测试其稳定性与水。可以预见，将建立一个新的用于稳定混合钙钛矿材料的范式。