Epitaxial Growth of CsPbX3 (X = Cl, Br, I) Perovskite Quantum Dots via Surface Chemical Conversion of Cs2GeF6 Double Perovskites: A Novel Strategy for the Formation of Leadless Hybrid Perovskite Phosphors with Enhanced Stability. Issue 16 (25th February 2019)

• Record Type: Journal Article
• Authors: Wei, Yi; Li, Kai; Cheng, Ziyong; Liu, Manman; Xiao, Hui; Dang, Peipei; Liang, Sisi; Wu, Zhijian; Lian, Hongzhou; Lin, Jun
• Is Part Of: Advanced materials. Volume 31:Issue 16(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-02-25
• Subjects: enhanced stability -- epitaxial growth -- leadless perovskite -- quantum dots; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.201807592
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Lead halide perovskites (LHPs) have received increased attention owing to their intriguing optoelectronic and photonic properties. However, the toxicity of lead and the lack of long‐term stability are potential obstacles for the application of LHPs. Herein, the epitaxial synthesis of CsPbX3 (X = Cl, Br, I) perovskite quantum dots (QDs) by surface chemical conversion of Cs2 GeF6 double perovskites with PbX2 (X = Cl, Br, I) is reported. The experimental results show that the surface of the Cs2 GeF6 double perovskites is partially converted into CsPbX3 perovskite QDs and forms a CsPbX3 /Cs2 GeF6 hybrid structure. The theoretical calculations reveal that the CsPbBr3 conversion proceeds at the Cs2 GeF6 edge through sequential growth of multiple PbBr6 4− layers. Through the conversion strategy, luminescent and color‐tunable CsPbX3 QDs can be obtained, and these products present high stability against decomposition due to anchoring effects. Moreover, by partially converting red emissive Cs2 GeF6 :Mn 4+ to green emissive CsPbBr3, the CsPbBr3 /Cs2 GeF6 :Mn 4+ hybrid can be employed as a low‐lead hybrid perovskite phosphor on blue LED chips to produce white light. The leadless CsPbX3 /Cs2 GeF6 hybrid structure with stable photoluminescence opens new paths for the rational design of efficient emission phosphors and may stimulate the design of other functional CsPbX3 /Cs‐containing hybrid structures. Abstract : Leadless hybrid perovskites are obtained by the epitaxial synthesis of CsPbX3 (X = Cl, Br, I) perovskite quantum dots through surface chemical conversion of Cs2 GeF6 double perovskites with PbX2 (X = Cl, Br, I). The obtained CsPbBr3 /Cs2 GeF6 products show high color purity and enhanced stability, indicating their potential application in lighting devices.