ECCS-EPSRC: Superlattice Architectures for Efficient and Stable Perovskite LEDs

ECCS-EPSRC：用于高效稳定钙钛矿 LED 的超晶格架构

• 批准号: 2141949
• 负责人: Seth Marder
• 金额: $ 40万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2141949&HistoricalAwards=false
• 关键词: ECCS; EPSRC; Superlattice; Architectures; Efficient

This proposal will develop thin-film metal-halide perovskite light-emitting diodes (LEDs) with high efficiencies. Standard inorganic LEDs, such as blue indium-gallium nitride, rely on the ability to p-dope and n-dope the hole- and electron-injecting layers, and to construct multi-quantum-well structures within which electrons/holes are confined and emit light, all in a heteroepitaxial structure. This allows close to thermodynamic efficiency operation for red and blue, but not yet for green (where nitrides show substantial losses). In contrast, organic LEDs (OLEDs) are assembled as stacks of different molecular materials, with band-edge positions selected to allow electron or hole transport to the recombination zone. ‘Doping’ through charge-transfer reactions with redox-active additives is used to assist injection from electrodes, but is not possible in the bulk. Though commercialized for displays, OLEDs require drift fields to overcome injection barriers, show very low carrier mobilities, and operate at voltages well above the emission bandgap. As outlined in our ‘track-record’ above, the team successfully adopted the OLED architecture for thin-film LEDs made with metal-halide perovskites. The critical components in this work will be developing: (a) a 2D/3D superlattice that confines e-h pairs, but with a tuneable “well depth” in order to minimize drive voltage requirements will be used in these to achieve good charge trapping, (b) spacer layers of perovskite that keep charge carriers away from the transport layers to avoid quenching; (c) and (d) hole- and electron-transport layers engineered to give ohmic injection at the perovskite interfaces, through chemical tuning and doping (ensuring that trap/quenching states associated with doping are far enough away from the emissive perovskite zone) and designed to give ohmic contacts at the two electrodes. This requires advances across a range of materials chemistry, materials processing, and semiconductor engineering tasks, underpinned by advanced characterization techniques. Light-emitting diodes (LEDs) are devices that are used in many of today’s displays, such as those used in televisions and cell phones, and can also increasingly in lighting. For these applications red-, green-, and blue-emitting LEDs are needed. However, green-emitting LEDs that are energy efficient and that are stable are particularly challenging to develop. This proposal is focused on developing efficient green-emitting devices based on a class of materials known as metal-halide perovskites. In particular, teams at the Universities of Cambridge (UK), Oxford (UK), and Colorado (USA) will collaborate with one another to solve engineering problems facilitating such devices. This work may result in new commercially viable LED technologies, as well as other new applications for metal-halide perovskites. As well as having potential impacts on the emerging semiconductor industry in the UK and USA, this project will: provide a US postdoctoral researcher with experience in organic and metal-organic synthesis and a range of physical characterization methods, and with the opportunity to participate in a close international inter-institute collaboration; and help support the education and training of women and underrepresented minority students.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.

该提案将效率为标准的无机LED硝化物，将其固定二极管发光二极管（LED）。并且要限制电子/孔的消耗量 - 孔结构，这允许对红色和蓝色的热力学功效接近，但对绿色的氮化物却没有实质性的损失（OLEDS）。将其作为不同分子材料的堆栈组装，允许电子或重组区的孔传输要克服注入屏障，显示出非常低的载体迁移率，并在我们上面概述的发射带电压下以电压运行。这项工作将开发：（a）限制E-H对的2D/3D超级晶格，但具有可调的“良好深度”，以最大程度地减少电压需求，将使贝洛维斯岛的Beuull Beuill Acer层保持较小避免;（d）孔和电子传输层次在Tovskite界面上进行欧姆注入，尽管化学调谐和掺杂帽子陷阱/淬火状态与掺杂型相关的状态远离发射的perovskite区域）在两种材料化学范围内的电极上的接触，并通过高级表征的技术（例如电视和手机）进行的。 - 需要的LED尤其是剑桥大学（英国），牛津大学和科罗拉多州（美国）的团队将彼此合作，以解决此类设备的工程问题。金属甲基钙钛矿的新应用以及对英国和美国的新兴半导体行业的潜在影响，这位具有有机和金属有机合成的博士后研究人员使用基金会的知识分子优点和更广泛的审查标准，参加了妇女的亲密国际合作；