北京时间2月20日，国际权威学术期刊《自然》（Nature）在线发表南开大学化学学院教授袁明鉴、中国科学院院士陈军、研究员章炜领衔的科研团队在新型钙钛矿超高清显示技术领域的最新研究进展。 该研究题为“Perovskite heteroepitaxy for high-efficiency and stable pure-red LEDs”。团队针对新型钙钛矿超高清显示技术中纯红光CsPbI3钙钛矿量子点材料相稳定性差这一世界难题，率先提出“外延异质结界面应力操控”策略，首次利用全溶液法实现钙钛矿范德华外延异质结的大面积原位可控制备，成功突破材料稳定性与器件性能双重瓶颈，研发出高效率与高稳定性兼备的纯红光钙钛矿电致发光器件 (LED)，为下一代超高清显示技术发展提供了关键技术支撑，标志着在该领域的重大技术突破。 Perovskite materials possess unique advantages such as high fluorescence quantum yield, high color purity, and wide color gamut, making them ideal materials for the next generation of ultra-high-definition display technologies. As one of the three primary colors (red, green, blue), pure red perovskite LEDs are critical for 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 been hindered by the challenge of poor material stability. CsPbI3 perovskite quantum dots exhibit size-tunable bandgap emission, making them ideal materials for achieving pure red perovskite LEDs. However, CsPbI3 perovskites suffer from poor intrinsic phase stability; their bulk materials readily undergo phase transitions at room temperature, converting into non-optically active phases. More critically, CsPbI3 perovskite quantum dots, due to their extremely small particle size and extremely high surface energy, are almost unable to stably exist at room temperature. Therefore, understanding the phase transition mechanisms of metastable CsPbI3 perovskite quantum dots, developing new strategies to enhance phase stability based on this understanding, and thereby achieving pure red perovskite LEDs that combine high efficiency with high stability, is an inevitable requirement for promoting the application of perovskite luminescent materials in ultra-high-definition displays. Figure: Perovskite van der Waals epitaxial heterostructure materials, light-emitting films, and LED devices constructed via all-solution in-situ methods Professor Yuan Mingjian, Academician Chen Jun, and Researcher Zhang Wei lead a research team that has long been engaged in the study of high-performance semiconductor optoelectronic conversion materials and devices. During the continuous exploration of high-efficiency and high-stability perovskite optoelectronic materials, the research team discovered that manipulating lattice stress to achieve local lattice distortion in perovskites can significantly enhance the phase stability of metastable perovskite materials. Based on these findings, the research team utilized ligand molecular structure design and regulation to report for the first time a novel strategy using an all-solution in-situ method to prepare perovskite van der Waals epitaxial heterostructures to enhance the phase stability of perovskite quantum dots. Combining aberration-corrected transmission electron microscopy characterization with density functional theory research, the research team revealed for the first time the mechanism by which interfacial stress in perovskite epitaxial heterostructures regulates the lattice structure of perovskite quantum dots . Research shows that lattice distortion induced by interfacial stress can effectively inhibit the phase transition process of CsPbI3 perovskite quantum dots, significantly enhancing material stability. The obtained CsPbI3 perovskite quantum dot conductive films exhibit excellent stability and optoelectronic properties. On this basis, the team successfully developed pure red perovskite LEDs that combine world-class performance and stability, solving the bottleneck problem that has long plagued this field . This study is based on fundamental chemistry disciplines , bringing together multidisciplinary strengths in materials, physics, and semiconductor devices . It has developed advanced transmission electron microscopy (TEM) structural characterization techniques, achieving the creation of new van der Waals epitaxial heterostructures in perovskites. It has overcome the core stability challenge of pure red-light perovskite LED materials, with potential to further drive technological innovation in the ultra-high-definition display industry . This work was led by Nankai University, jointly completed with eight domestic and international institutions including Beijing Normal University, the University of Hong Kong, EPFL, King Saud University, etc., Nankai University is the first completing unit and the sole corresponding unit for this paper . 化学学院博士研究生韦科妤、周峒和特聘研究员姜源植为该论文共同第一作者。袁明鉴教授、陈军院士、章炜研究员为该论文通讯作者。袁明鉴教授负责材料与器件的整体设计，陈军院士主要负责分子结构设计与表征平台建设，章炜研究员负责透射电镜表征工作。 The above research work received support from the National Science Fund for Distinguished Young Scholars, the National Natural Science Foundation of China Innovative Groups projects, and was carried out relying on platforms such as the State Key Laboratory of Special Chemical Power Sources, the Frontier Science Center for Creation of New Organic Substances, and the Wuchuang Haihe Laboratory .
Source: Nankai University Media Convergence Center
