Mn-derived Cs4PbX6 nanocrystals with stable and tunable wide luminescence for white light-emitting diodes. Issue 10 (17th February 2022)

• Record Type: Journal Article
• Authors: Shi, Wenbin; Zhang, Xiao; Matras-Postolek, Katarzyna; Yang, Ping
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 10(2022)
• Page Start: 3886
• Page End: 3893
• Publication Date: 2022-02-17
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2tc00014h
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : The band gap of Cs4 PbX6 NCs was adjusted by Mn doping (Mn:Cs4 PbX6 ), resulting in adjusted photoluminescence (PL) peaks and high PL efficiency. White light-emitting diodes were fabricated using the NCs with a Internationale de I'Eclairagechromaticity coordinates of (0.3229, 0.3037). Abstract : Cs4 PbX6 nanocrystals (NCs) are perovskite derivatives with a wide band gap, but their application is limited because of their non-luminescence characteristics in the visible range. In this paper, the band gap of Cs4 PbX6 NCs was adjusted via Mn doping (Mn:Cs4 PbX6 ). Mn doping changes the photoluminescence (PL) properties of the NCs. A PL peak at 610 nm is observed at λ ex = 289 nm, which confirms that Mn ions are introduced in the lattice of the Cs4 PbX6 NCs. The effect of Mn ions on the PL properties of the Cs4 PbX6 NCs is investigated by changing the Pb : Mn molar ratio. When the Pb : Mn ratio is 1 : 1, the PL quantum yield of the NCs reaches 23.1%. Transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction (XRD) analysis indicate that Mn ions were successfully introduced in the Cs4 PbCl6 NCs. Raman spectroscopy further proves that the Cs4 PbCl6 NCs possess high crystallinity. Two PL peaks at 355 and 610 nm are observed for the Mn:Cs4 PbX6 NCs. The PL decay plots of the Mn:Cs4 PbCl6 NCs show that the lifetime at λ em = 355 nm reduces with increasing Pb : Mn molar ratio while the lifetime at λ em = 610 nm increases, suggesting that the process of photo exciton transfer occurs from Pb to Mn ions. Due to their high stability, white light-emitting diodes (LEDs) were fabricated using CsPb(Cl/Br)3, CsPbBr3 and Mn:Cs4 PbCl6 NCs as color conversion layers using a 280 nm commercial LED chip as the excitation source. The Internationale de I'Eclairage chromaticity coordinates of the white LED are located at (0.3229, 0.3037).