Chinese scientists overcome technical difficulties of pure red perovskite LED

The research team led by Professor Yuan Mingjian, Academician Chen Jun and Researcher Zhang Wei has long been engaged in the research of high-performance semiconductor photoelectric conversion materials and devices. In the process of continuously exploring high-efficiency and high-stability perovskite photoelectric materials, the research team found that the phase stability of metastable perovskite materials can be significantly enhanced by achieving local lattice distortion of perovskite through lattice stress manipulation. Based on the above findings, the research team used the design and regulation 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 all-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 regulatory mechanism of the interface stress of perovskite epitaxial heterostructure on the lattice structure of perovskite quantum dots.

The study shows 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 photoelectric properties. On this basis, the team successfully developed a pure red perovskite LED with world-class performance and stability, solving the bottleneck problem that has long plagued this field.

Based on the basic discipline of chemistry, the research brings together multidisciplinary forces such as materials, physics, and semiconductor devices, develops advanced transmission electron microscope structure characterization technology, realizes the creation of new materials for perovskite van der Waals epitaxial heterojunction, and overcomes the stability problem of the core material of pure red perovskite LED, which is expected to further promote technological innovation in the ultra-high-definition display industry.