近日，英国剑桥大学的Akshay Rao及其研究小组与牛津大学的Robert L. Z. Hoye等人合作并取得一项新进展。经过不懈努力，他们实现钙钛矿纳米片超晶格的直接线偏振电致发光。相关研究成果已于2024年2月23日在国际知名学术期刊《自然—光子学》上发表。
该研究团队展示了以CsPbI3钙钛矿纳米片超晶格为基础制作的发光二极管，可直接发射线偏振光。研究人员通过调整溶剂的蒸汽压力，精细控制纳米薄片的自组装方向（朝上或边朝上），从而调控其跃迁偶极矩。由于纳米片的高度均匀排列和强大的量子及介质约束，薄膜水平上实现了大的激子精细结构分裂。因此，所制备的纯红色发光二极管展现出了高达74.4%的线偏振电致发光，且无需使用任何光子结构。
这一成果证明了钙钛矿纳米片作为线偏振光源的潜力，为下一代三维显示和光通信技术的发展开辟了新的道路，提供了一个高度通用、可溶液处理的系统。
据悉，偏振光在众多应用领域中扮演着关键角色，但当前主要通过过滤非偏振光来产生，这一过程中不仅会造成大量的能量损耗，还需额外配备光学器件。
附：英文原文
Title: Direct linearly polarized electroluminescence from perovskite nanoplatelet superlattices
Author: Ye, Junzhi, Ren, Aobo, Dai, Linjie, Baikie, Tomi K., Guo, Renjun, Pal, Debapriya, Gorgon, Sebastian, Heger, Julian E., Huang, Junyang, Sun, Yuqi, Arul, Rakesh, Grimaldi, Gianluca, Zhang, Kaiwen, Shamsi, Javad, Huang, Yi-Teng, Wang, Hao, Wu, Jiang, Koenderink, A. Femius, Torrente Murciano, Laura, Schwartzkopf, Matthias, Roth, Stephen V., Mller-Buschbaum, Peter, Baumberg, Jeremy J., Stranks, Samuel D., Greenham, Neil C., Polavarapu, Lakshminarayana, Zhang, Wei, Rao, Akshay, Hoye, Robert L. Z.
Issue&Volume: 2024-02-23
Abstract: Polarized light is critical for a wide range of applications, but is usually generated by filtering unpolarized light, which leads to substantial energy losses and requires additional optics. Here we demonstrate the direct emission of linearly polarized light from light-emitting diodes made of CsPbI3 perovskite nanoplatelet superlattices. The use of solvents with different vapour pressures enables the self-assembly of the nanoplatelets with fine control over their orientation (either face-up or edge-up) and therefore their transition dipole moment. As a result of the highly uniform alignment of the nanoplatelets, as well as their strong quantum and dielectric confinement, large exciton fine-structure splitting is achieved at the film level, leading to pure red light-emitting diodes with linearly polarized electroluminescence exhibiting a high degree of polarization of 74.4% without any photonic structures. This work demonstrates the potential of perovskite nanoplatelets as a promising source of linearly polarized light, opening up the development of next-generation three-dimensional displays and optical communications from a highly versatile, solution-processable system.
DOI: 10.1038/s41566-024-01398-y
Source: https://www.nature.com/articles/s41566-024-01398-y