Eager: Tuning Performance in Perovskite Thermoelectric Devices with Organic Radical Dopants

非技术：热电设备在未来的能源领域有着巨大的前景。它们将废热转化为可用的电力，并能按需制冷或供热。尽管热电器件具有潜力，但其低效率限制了其应用。要使这一有前途的技术成为现实，需要在热电器件中使用的材料性能方面取得进展。pi将研究热电应用的新材料家族：具有有机和无机成分的混合金属卤化物钙钛矿。学生将接受材料科学和工程方面的培训。该项目将影响材料科学和电子社区，并激励未来的科学家和工程师致力于可持续能源解决方案。技术：混合金属卤化物钙钛矿是一种低导热材料，从性能和成本的基础上来看，在实际的溶液加工热电器件中具有明显的优势。然而，用钙钛矿系统制造热电器件的努力很少。这种研究和实现的缺乏主要是由于找到一种通过直接掺杂策略有效控制器件载流子浓度和电导率的方法的关键挑战。由于电荷筛选和典型钙钛矿系统的耐缺陷性质，传统的掺杂方法主要集中在晶格中的原子取代上，不适用于卤化物钙钛矿。因此，为了克服这一关键挑战，必须改变钙钛矿器件中掺杂的原型。通过将含自由基配体结合到实际的钙钛矿晶格中，以作为热电器件的分子内掺杂剂，将解决这一关键机会。该项目是基于pi先前通过将封闭壳有机配体结合到材料的晶体结构中来操纵钙钛矿基器件的光电性能的工作，以及先前使用自由基基掺杂剂增强聚合物热电器件性能的成功。这些自由基掺杂剂的包含将允许通过分子内手段随时调整载流子浓度以及与半导体材料相关的电导率和导热率。该项目将能够在新型印刷电子材料中操纵关键的结构-性能-性能关系，并在此过程中展示高性能设备。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nontechnical:Thermoelectric devices hold great promise for the future energy landscape. They convert waste heat into usable electricity and can provide on demand cooling or heating. Despite their potential, the low efficiency of thermoelectric devices has limited their adoption. Advances in the properties of materials used in thermoelectric devices are needed to make this promising technology a reality. The PIs will investigate a new family of materials for thermoelectric applications: hybrid metal halide perovskites with organic and inorganic components. Students will receive training in materials science and engineering. This project will impact the materials science and electronics communities and inspire future scientists and engineers dedicated to sustainable energy solutions.Technical:Hybrid metal halide perovskites are low-thermal conductivity materials with clear benefits in practical, solution-processed thermoelectric devices from a performance and cost basis. Yet, little effort has been placed in fabricating thermoelectric devices from perovskite systems. This lack of study and implementation is mainly due to the key challenge in finding a means by which to effectively control the charge carrier concentration and electrical conductivity of the devices through straightforward doping strategies. The conventional approach to doping that is focused on atomic substitution in the lattice does not work for halide perovskites due to charge screening and the defect-tolerant nature of typical perovskite systems. Therefore, a shift in archetype regarding doping in perovskite devices must be had in order to overcome this key challenge. This critical opportunity will be addressed by incorporating radical-containing ligands into the actual perovskite crystal lattice in order to serve as intramolecular dopants for the thermoelectric devices. This project is based on the PIs' prior work in manipulating the optoelectronic properties of perovskite-based devices by incorporating closed-shell organic ligands into the crystal structures of the materials and previous success of using radical-based dopants to enhance the performance of polymer thermoelectric devices. Inclusion of these radical dopants will allow for the ready tuning of the carrier concentrations and electrical and thermal conductivities associated with the semiconducting materials through intramolecular means. This project will enable manipulation of the key structure-property-performance relationships in a novel class of printed electronic materials, and in doing so, demonstrate high-performance devices.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.