Chinese scientists overcome technical problems of pure red perovskite LED

Nankai University announced the latest research progress in the field of new perovskite ultra-high-definition display technology led by a scientific research team led by Professor Yuan Mingjian of the School of Chemistry, Academician Chen Jun of the Chinese Academy of Sciences, and researcher Zhang Wei.

Relevant results were published online in the top international journal "Nature" (IT Home attached DOI: 10.1038/s41586-024-08503-9).

In response to the world-wide problem of poor phase stability of pure red CsPbI3 perovskite quantum dot materials in new perovskite ultra-high-definition display technology, the team took the lead in proposing the "epitaxial heterojunction interface stress control" strategy. It used the full solution method for the first time to achieve large-area in-situ controllable preparation of perovskite van der Waals epitaxial heterojunctions. It successfully broke through the dual bottlenecks of material stability and device performance, and developed a pure red perovskite electroluminescent device with both high efficiency and high stability. (LED), provides key technical support for the development of next-generation ultra-high-definition display technology, marking a major technological breakthrough in this field.

Perovskite materials have unique advantages such as high fluorescence quantum yield, high color purity, and wide color gamut. potential and is considered an ideal material for next-generation ultra-high-definition display technology. As one of the three primary colors of red, green and blue, pure red perovskite LEDs are crucial to realizing next-generation ultra-high-definition display systems that meet the Rec. 2100 ultra-wide color gamut standard. However, pure red perovskite LEDs have long suffered from poor material stability.

CsPbI3 perovskite quantum dots have size-dependent tunable bandgap luminescence and are ideal materials for realizing pure red-emitting perovskite LEDs. However, the intrinsic phase stability of CsPbI3 perovskite is poor, and its bulk material is prone to phase transition at room temperature and is converted into an optically inactive phase. What’s even more serious is that CsPbI3 perovskite quantum dots are almost unable to exist stably at room temperature due to their extremely small particle size and extremely large surface energy. Therefore, understanding the phase transition mechanism of metastable CsPbI3 perovskite quantum dots, and developing new strategies to improve high-efficiency phase stability based on this, and then realizing pure red perovskite LEDs with both high efficiency and high stability are inevitable needs to promote the application of perovskite luminescent materials in ultra-high-definition displays.


The scientific research team led by Professor Yuan Mingjian, Academician Chen Jun, and Researcher Zhang Wei has been engaged in the research of high-performance semiconductor photoelectric conversion materials and devices for a long time. In the process of continuing to explore high-efficiency and high-stability perovskite optoelectronic materials, the research team discovered that local lattice distortion of perovskite through lattice stress manipulation can significantly enhance the phase stability of metastable perovskite materials. Based on the above findings, the research team used the design and control of ligand molecular structure to report for the first time a new strategy for in-situ preparation of perovskite van der Waals epitaxial heterojunctions by a full solution method to improve the phase stability of perovskite quantum dots. Combining spherical aberration-corrected transmission electron microscopy characterization and density functional theory research, the research team revealed for the first time the regulation mechanism of the interfacial stress of the perovskite epitaxial heterostructure on the perovskite quantum dot lattice structure.

Studies have shown that the lattice distortion induced by interface stress can effectively inhibit the phase transition process of CsPbI3 perovskite quantum dots and significantly improve the stability of the material. The obtained CsPbI3 perovskite quantum dot conductive film has excellent stability and optoelectronic properties. On this basis, the team successfully developed a product with world-class performance and stability. Qualitative pure red perovskite LED solves the bottleneck problem that has long plagued the field.

This research is based on the basic disciplines of chemistry, bringing together materials, physics, semiconductor devices and other multidisciplinary forces to develop advanced transmission electron microscopy structural characterization technology, realizing the creation of new materials for perovskite van der Waals epitaxial heterojunctions, overcoming the stability problem of pure red perovskite LED core materials, and is expected to further promote technological innovation in the ultra-high-definition display industry.

This work was led by Nankai University and completed in collaboration with 8 domestic and foreign institutions including Beijing Normal University, University of Hong Kong, Ecole Polytechnique Fédérale de Lausanne, and King Saud University. Nankai University was the first unit to complete the paper and the only corresponding unit.

Ph.D. candidates Wei Keyu and Zhou Dong from the School of Chemistry and distinguished researcher Jiang Yuanzhi are the co-first authors of the paper. Professor Yuan Mingjian, Academician Chen Jun, and Researcher Zhang Wei are the corresponding authors of the paper. Professor Yuan Mingjian is responsible for the overall design of materials and devices, Academician Chen Jun is mainly responsible for molecular structure design and characterization platform construction, and Researcher Zhang Wei is responsible for transmission electron microscopy characterization work.