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.
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.
