Enhancing stability of red perovskite nanocrystals through copper substitution for efficient light-emitting diodes. (August 2019)

• Record Type: Journal Article
• Authors: Zhang, Jibin; Zhang, Louwen; Cai, Ping; Xue, Xiaogang; Wang, Mingkui; Zhang, Jian; Tu, Guoli
• Is Part Of: Nano energy. Volume 62(2019)
• Page Start: 434
• Page End: 441
• Publication Date: 2019-08
• Subjects: CsPbBrI2 -- Perovskite nanocrystals -- Copper-substitution -- Stability -- Halide rich passivation -- Light-emitting diodes; 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.2019.05.027
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Red perovskite nanocrystals (NCs) are important for efficient perovskite light-emitting diodes (PeLEDs). However, the implementation of these red perovskite NCs are hindered because of their low structural stability. In the present work, highly stable and luminescent red perovskite CsPbBrI2 NCs were achieved through copper substitution and halide rich passivation strategy. Because the ion radius of Cu 2+ (0.72 Å) is smaller than that of Pb 2+ (1.19 Å), divalent Cu 2+ cations can partly replace the Pb 2+ ions in the lattice structure of CsPbBrI2 NCs. We demonstrated that the incorporation of Cu 2+ ions can enhance formation energy, cause a slight lattice contraction, and hence stabilize the cubic phase of these NCs. On the other hand, Cu 2+ -substituted CsPbBrI2 NCs with higher luminescence were synthesized in a halide-rich passivation method. Benefiting from such an effective substitution and halide-rich strategy, these Cu 2+ -substituted CsPbBrI2 NCs has shown excellent performance with photoluminescence quantum yield (PL QY) (up to 94.8%) and an improved stability. The highly stable and luminescent Cu 2+ -substituted CsPbBrI2 NCs can function well as efficient light emitters toward the fabrication of high-performance red perovskite LEDs. Graphical abstract: Image 1 Highlights: Highly stable and luminescent red perovskite CsPbBrI2 NCs were achieved through copper substitution and halide-rich strategy. Bond strength of Pb-I of CsPbBrI2 NCs can be improved by the incorporation of Cu 2+ ions. The halide-rich Cu 2+ -substituted CsPbBrI2 NCs shown excellent photoluminescence quantum yield (PLQY) and ultrastability.