Bright and spectrally stable pure-red CsPb(Br/I)3 quantum dot LEDs realized by synchronous device structure and ligand engineering. (April 2023)

• Record Type: Journal Article
• Authors: Lu, Po; Lu, Min; Zhang, Fujun; Qin, Feisong; Sun, Siqi; Zhang, Yu; Yu, William W.; Bai, Xue
• Is Part Of: Nano energy. Volume 108(2023)
• Publication Date: 2023-04
• Subjects: CsPb(Br/I)3 -- Perovskite quantum dots -- Pure-red -- Light-emitting diodes -- Device structure and ligand engineering; EQE external quantum efficiency -- EL electroluminescence; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2023.108208
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: All-inorganic CsPbBrx I3−x perovskite quantum dots (PQDs) show great potential for pure-red light-emitting diodes (LEDs). However, spectral instability caused by ion migration at high electric fields and lower luminance limit its practical applications. Here, the ITO/ZnO/PEI/CsPbBrx I3−x PQDs/N, N, N-tris (4-(9-carbazolyl) phenyl) amine (TCTA) (3 nm)/1-bis [4-[N, N-di(4-tolyl)amino]-phenyl]-cyclohexane (TAPC)/MoO3 /Au device structure is first designed to reduce the overall operating voltage of the device by enhancing hole injection and transport, effectively avoiding ion migration under high electric fields, and then by post-treating CsPbBrx I3−x PQDs with n-octylphosphonic acid: K to remove surface defects and increase the activation energy of halogen migration, further suppressing ion migration while improving the optical properties of the material. Ultimately, the color-stable pure-red perovskite LED achieved a high luminance of 13730 cd m −2 at voltages as low as 4.9 V and a maximum EQE of 16.7%. Graphical Abstract: Spectrally stable pure-red perovskite nanocrystal LEDs with a maximum EQE of 16.7%, a maximum luminance of 13730 cd m −2 at voltage as low as 4.9 V, achieved through synchronous carrier transport balance regulation of the device structure and optimization of perovskite nanocrystal materials. ga1 Highlights: A high-performance pure-red perovskite quantum dot LED was prepared. The LED has a low operating voltage and high luminance. The LED has excellent spectral stability. The high-performance is achieved through device structure and ligand engineering.