Blue Light Emitting Diodes Based on Metal Halide Perovskites and Perovskite-Related Materials

电驱动蓝光发光二极管（LED）是现代电子产品中的重要组件，例如彩色显示器和固态照明，其市场规模达数十亿美元。迄今为止，基于无机半导体（如InGaN）的蓝光LED一直主导着市场，这些LED是通过涉及高温和高真空的昂贵工艺制造的。开发基于低成本材料的蓝光LED具有很大的科学和实际意义，这些材料可以在低温下容易地加工。可溶液加工的金属卤化物钙钛矿和钙钛矿相关材料最近已经作为用于高效和低成本LED的一类新的发光材料出现。虽然绿色、红色和近红外钙钛矿LED已经取得了很大进展，但蓝色LED远远落后，性能和稳定性极低。该研究旨在开发基于新型金属卤化物钙钛矿和钙钛矿相关材料的高效蓝光LED，并优化器件结构。该项目的成功将为金属卤化物钙钛矿和钙钛矿相关材料的材料化学，薄膜加工和器件物理学产生新的知识。它将对电子设备产生重大的技术影响，包括显示器、固态照明和柔性电子产品，并有可能彻底改变显示器和照明行业。该项目还将在多学科材料和能源研究方面教育和培训研究生和本科生，并通过各种社区外联活动，如科学展览和高中生夏令营，促进科学，技术，工程和数学（STEM）教育。技术说明：拟议的研究旨在开发基于金属卤化物钙钛矿和钙钛矿相关材料的高性能电驱动蓝色LED，通过确定新的钙钛矿材料，薄膜加工方法和器件架构。首先，将研究颜色调谐的新方法以从金属卤化物钙钛矿和钙钛矿相关材料获得高效的蓝色发射。其次，将开发用于制备具有受控形态、光学和电学性质的蓝光发射薄膜的溶液处理方法。拟议的研究将调查如何处理条件影响薄膜的性质和它们在器件中的性能。利用高度发光的蓝色发光薄膜，将进行器件集成和工程设计，以通过将它们与多层结构中的适当空穴和电子传输层集成来实现高效的电驱动LED。蓝光LED的稳定性将被研究，以揭示潜在的退化机制，从而开发提高稳定性的方法。最终，全面深入地了解结构-加工-性能-性能的关系，这将作为进一步开发蓝色发光材料和器件的指导方针。该项目将显著推进钙钛矿光电子领域，并通过地球丰富的材料和低成本加工提高蓝色LED的可持续性。该奖项反映了NSF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。

Electrically driven blue light emitting diodes (LEDs) are essential components in modern electronics, such as color displays and solid-state lighting, which have a market size of billions of dollars. To date, blue LEDs based on inorganic semiconductors, such as InGaN, have been dominating the market, which are manufactured by expensive processes involving high temperature and high vacuum. Developing blue LEDs based on low cost materials that can be facilely processed at low temperature are of great scientific and practical interest. Solution processable metal halide perovskites and perovskite-related materials have recently emerged as a new class of light emitting materials for efficient and low cost LEDs. While great progress has been achieved for green, red, and near-infrared perovskite LEDs, blue LEDs lag far behind with extremely low performance and stability. The proposed research aims to develop highly efficient blue LEDs based on new metal halide perovskites and perovskite-related materials with optimized device structures. The success of this project will generate new knowledge in materials chemistry, thin film processing, and device physics for metal halide perovskites and perovskite-related materials. It will have significant technological impacts on electronic devices, including displays, solid state lighting, and flexible electronics, with the potential to revolutionize the display and lighting industries. This project will also educate and train graduate and undergraduate students in multidisciplinary materials and energy research, and promote Science, Technology, Engineering and Mathematics (STEM) education through various community outreach activities, such as science exhibitions and summer camps for high school students. Technical Description: The proposed research aims to develop high performance electrically driven blue LEDs based on metal halide perovskites and perovskite-related materials, through identifying new perovskite materials, thin film processing methods, and device architectures. First, new approaches of color tuning will be investigated to obtain highly efficient blue emissions from metal halide perovskites and perovskite-related materials. Secondly, solution processing approaches will be developed for the preparation of blue emitting thin films with controlled morphological, optical, and electronic properties. The proposed research will investigate how the processing conditions affect the thin film properties and their performance in devices. With the highly luminescent blue emitting thin films, device integration and engineering will be carried out to achieve highly efficient electrically driven LEDs, by integrating them with proper hole and electron transport layers in a multilayer structure. The stability of blue LEDs will be studied to reveal potential degradation mechanisms, with which approaches to enhancing stability will be developed. Eventually, a comprehensive in-depth understanding of the structure-processing-property-performance relationships will be available, which would serve as a guideline for the further development of blue emitting materials and devices. This project will significantly advance the field of perovskite optoelectronics and improve sustainability of blue LEDs with earth-abundant materials and low-cost processing.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.