Understanding structural, optical, and thermoelectric properties of complex metal halides for energy applications

金属卤化物钙钛矿最近已经成为显著的太阳能吸收剂，例如，获得超过25%的光伏转换效率。该领域的领先材料含有铅元素，尽管它们具有优异的功率转换特性，但有毒，并且在长期使用时也不稳定。这些因素限制了其商业应用。有一个重要的机会来开发无铅，空气稳定的化合物，复制其铅类似物的有益特性，但要做到这一点，这些化合物的基本物理和化学必须得到更好的理解。在这里，我们建议研究复杂的金属卤化物和卤氧化物，重点是在能源技术中具有潜在应用的无铅材料。复杂的金属卤化物提供了广泛的参数空间;化学组成，晶体和电子结构的变化允许研究组成-结构功能关系，这是跨学科物理化学研究的理想机会，与EPSRC物理科学和能源主题保持一致，特别是在以下领域：先进材料，凝聚态物质：电子结构和能源应用材料。该项目的目的是合成和制备用于光伏和热电应用的新型复合金属卤化物材料。我们致力于了解化学成分、物理性质和功能之间的联系，以便在大的参数空间中导航，找到特殊的材料。该项目将专注于高质量样品的创新化学合成，例如，通过气相传输，溶液和凝胶相晶体生长，以及通过物理和化学方法形成薄膜。最先进的表征，例如，衍射（X射线和中子），光电子能谱，使用稳态和时间分辨方法的光学表征，将由学生承担。最后，将进行功能测试，例如通过构建光伏设备，测试热电参数或测试光催化反应器中的材料。通过将晶体结构、电子结构、光学性质、输运性质等基本性质与功能联系起来，我们将更好地了解这些迷人的材料，并将更好地在光致发光、热电、发光材料和催化剂等领域生产高效能源材料。

Metal Halide perovskites have recently emerged as remarkable solar energy absorbers, for example, attaining photovoltaic conversion efficiencies exceeding 25% . The leading materials in the field contain the element lead, and despite their excellent power conversion properties, are toxic and also unstable on extended use. These factors limit their commercial application. There is a significant opportunity to develop lead-free, air-stable compounds that replicate the beneficial properties of their Pb analogues, but to do this, the fundamental physics and chemistry of these compounds must be better understood. Here we propose to study complex metal halides and oxy-halides, focusing on lead-free materials that have potential applications in energy technology. The complex metal halides offer a wide parameter space; changes to chemical composition, crystal and electronic structure permit the study of composition-structure function relationships, and this acts as an ideal opportunity for interdisciplinary Physics-Chemistry research, aligning with the EPSRC Physical Sciences and Energy Themes, and specifically the areas: Advanced Materials, Condensed matter: electronic structure, and Materials for Energy Applications.The aim of the project is to synthesise and characterise new complex metal halide materials for photovoltaic and thermoelectric applications. We seek to understand the link between chemical composition, physical properties, and function, to allow navigation of large parameter space to find exceptional materials.The project will focus on innovative chemical synthesis of high-quality samples, for example, by vapour phase transport, solution and gel phase crystal growth, and thin film formation by physical and chemical methods. State of the art characterisation, for example, diffraction (X-ray and neutron), photoemission spectroscopy, optical characterisation using steady state and time resolved methods, will be undertaken by the student. Lastly, functional testing, for example by building photovoltaic devices, testing thermoelectric parameters, or testing materials in a photocatalytic reactor, will be carried out. Together, by linking fundamental properties, such as crystal structure, electronic structure, optical properties, transport properties to function, we will gain better understanding of these fascinating materials, and will be better placed to produce highly efficient energy materials in fields such as photovoltaics, thermoelectrics, luminescent materials and catalysts.