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

非技术性：热电设备对未来的能源前景大有可为。它们将废热转化为可用电力，并可按需提供制冷或供暖。尽管有潜力，但热电设备的低效率限制了它们的采用。要使这项有希望的技术成为现实，需要在热电设备所用材料的性能方面取得进展。PIS将研究一类用于热电应用的新材料：含有有机和无机成分的杂化金属卤化物钙钛矿。学生将接受材料科学和工程方面的培训。该项目将对材料科学和电子界产生影响，并激励未来致力于可持续能源解决方案的科学家和工程师。技术：混合金属卤化物钙钛矿是一种低导热材料，从性能和成本角度来看，在实用的溶液处理热电设备中具有明显的好处。然而，在用钙钛矿系统制造热电设备方面，几乎没有什么努力。这种缺乏研究和实施的主要原因是，在寻找一种通过直接的掺杂策略有效控制器件的电荷载流子浓度和电导率的方法方面存在关键挑战。由于电荷屏蔽和典型钙钛矿体系的缺陷容忍性，专注于晶格中原子替代的传统掺杂方法不适用于卤化物钙钛矿。因此，为了克服这一关键挑战，必须改变关于钙钛矿型器件中掺杂的原型。这一关键的机会将通过在实际的钙钛矿晶格中加入含有自由基的配体来实现，以便作为热电设备的分子内掺杂剂。这个项目是基于PI之前通过在材料的晶体结构中加入闭壳有机配体来操纵钙钛矿型器件的光电性能以及之前成功地使用基于自由基掺杂剂来提高聚合物热电器件的性能而开展的。这些自由基掺杂剂的加入将允许通过分子内手段随时调节与半导体材料相关的载流子浓度以及电导和热导。该项目将能够操纵一类新型印刷电子材料中的关键结构-性能-性能关系，并在这样做的过程中展示高性能设备。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.