Collaborative Research: Interfacial Engineering for Stabilizing Hybrid Perovskites and Devices

非技术概述高效、低成本的发光二极管(LED)对美国未来的能源格局至关重要。它们被广泛应用于显示器和照明。目前的技术使用高温和高真空进行材料加工和器件制造，这是对能源和基础设施的要求。在这个项目中，基于一种新型半导体的LED器件--所谓的有机-无机杂化钙钛矿--将被研究。这些材料表现出LED应用所需的优异的光学和光电性能。此外，它们可以在温和的条件下进行低温加工，使器件的制造和集成变得容易得多。这项研究将使未来的LED设备成为可扩展和经济高效的。该项目还将为本科生和研究生提供跨学科的培训，为他们提供半导体技术领域未来职业所需的批判性思维和解决问题的技能。技术摘要有机-无机杂化钙钛矿材料在低成本、节能光电子学(例如LED和太阳能电池)方面显示出巨大的潜力。然而，基于钙钛矿的可行器件的开发受到材料和器件不稳定性的限制。在导致性能损失的因素中，离子迁移似乎是这类新半导体的固有因素，仍然具有绕过的挑战性。该项目旨在通过界面工程找到稳定钙钛矿型发光二极管的新方法。对这项研究的成功至关重要的三个问题将得到解答：(1)钙钛矿型器件中的哪个界面更容易发生离子迁移？(2)在晶界和界面上引入“非本征”界面层能抑制离子迁移吗？(3)实现这种界面层的合适技术是什么？利用材料化学和设备物理方面的综合专业知识，合作团队将揭示界面在材料降解中的基本作用，并提供稳定钙钛矿设备的实用策略。该项目的最终目标是打破目前设备稳定性的天花板，展示具有1000小时工作寿命的钙钛矿型LED。在更广泛的范围内，该项目中建立的界面工程方法也将适用于其他钙钛矿型器件，如太阳能电池和光电探测器，这些器件从材料选择到器件架构都有许多与钙钛矿型LED的共同特征。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。

AbstractNon-Technical SummaryHighly efficient and low-cost light emitting diodes (LEDs) are critical for the future energy landscape in the United States. They are widely used in displays and lighting. Current technologies use high temperature and high vacuum for materials processing and device fabrication, which are energy- and infrastructure-demanding. In this project, LED devices based on a new type of semiconductors—the so-called organic-inorganic hybrid perovskites—will be studied. These materials exhibit excellent optical and optoelectronic properties required for LED applications. In addition, they can be processed at low temperature under mild conditions, making the device fabrication and integration much easier. This research will enable future LED devices that are scalable and cost-effective. This project will also provide interdisciplinary training to undergraduate and graduate students, providing them with critical-thinking and problem-solving skills needed for future careers in areas of semiconductor technology.Technical SummaryOrganic-inorganic hybrid perovskites have shown tremendous potential for low-cost, energy-efficient optoelectronics (e.g. LEDs and solar cells). Development of viable devices based on the perovskites, however, has been inhibited by materials and device instability. Among the factors that are responsible for the performance loss, ion migration appears to be intrinsic to this new class of semiconductors and remains challenging to be circumvented. This project aims to identify new ways to stabilize perovskite-LEDs by interfacial engineering. Three questions that are critical to the success of the proposed research will be answered: (1) which interface in perovskite devices is more vulnerable to ion migration? (2) could the ion migration be suppressed by introducing “extrinsic” interlayers at the grain boundary and interface? (3) what are the suitable techniques for implementing such interlayers? Leveraging comprehensive expertise on materials chemistry and device physics, the collaborative team will unravel fundamental roles of the interfaces in materials degradation and provide a practical strategy for stabilizing perovskite devices. The ultimate goal of the project is to break the current ceiling of device stability and demonstrate perovskite-LEDs with 1000-hour operation lifetime. On a broader scope, the approach of interfacial engineering established in this project will also be applicable to other perovskite devices such as solar cells and photodetectors, which share many common features with perovskite-LEDs from materials selection to device architecture.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.