Unveiling the Photo- and Thermal-Stability of Cesium Lead Halide Perovskite Nanocrystals.

Autor: Boote BW; Department of Chemistry, Iowa State University.; Ames Laboratory, U.S. Department of Energy, Ames, Iowa, 50011-3111, United States., Andaraarachchi HP; Department of Chemistry, Iowa State University.; Ames Laboratory, U.S. Department of Energy, Ames, Iowa, 50011-3111, United States., Rosales BA; Department of Chemistry, Iowa State University., Blome-Fernández R; Department of Chemistry, Iowa State University., Zhu F; Department of Chemistry, Iowa State University., Reichert MD; Department of Chemistry, Iowa State University., Santra K; Department of Chemistry, Iowa State University.; Ames Laboratory, U.S. Department of Energy, Ames, Iowa, 50011-3111, United States., Li J; Department of Chemistry, Iowa State University.; Ames Laboratory, U.S. Department of Energy, Ames, Iowa, 50011-3111, United States., Petrich JW; Department of Chemistry, Iowa State University.; Ames Laboratory, U.S. Department of Energy, Ames, Iowa, 50011-3111, United States., Vela J; Department of Chemistry, Iowa State University.; Ames Laboratory, U.S. Department of Energy, Ames, Iowa, 50011-3111, United States., Smith EA; Department of Chemistry, Iowa State University.; Ames Laboratory, U.S. Department of Energy, Ames, Iowa, 50011-3111, United States.
Jazyk: angličtina
Zdroj: Chemphyschem : a European journal of chemical physics and physical chemistry [Chemphyschem] 2019 Oct 16; Vol. 20 (20), pp. 2647-2656. Date of Electronic Publication: 2019 Oct 01.
DOI: 10.1002/cphc.201900432
Abstrakt: Lead halide perovskites possess unique characteristics that are well-suited for optoelectronic and energy capture devices, however, concerns about their long-term stability remain. Limited stability is often linked to the methylammonium cation, and all-inorganic CsPbX 3 (X=Cl, Br, I) perovskite nanocrystals have been reported with improved stability. In this work, the photostability and thermal stability properties of CsPbX 3 (X=Cl, Br, I) nanocrystals were investigated by means of electron microscopy, X-ray diffraction, thermogravimetric analysis coupled with FTIR (TGA-FTIR), ensemble and single particle spectral characterization. CsPbBr 3 was found to be stable under 1-sun illumination for 16 h in ambient conditions, although single crystal luminescence analysis after illumination using a solar simulator indicates that the luminescence states are changing over time. CsPbBr 3 was also stable to heating to 250 °C. Large CsPbI 3 crystals (34±5 nm) were shown to be the least stable composition under the same conditions as both XRD reflections and Raman bands diminish under irradiation; and with heating the γ (black) phase reverts to the non-luminescent δ phase. Smaller CsPbI 3 nanocrystals (14±2 nm) purified by a different washing strategy exhibited improved photostability with no evidence of crystal growth but were still thermally unstable. Both CsPbCl 3 and CsPbBr 3 show crystal growth under irradiation or heat, likely with a preferential orientation based on XRD patterns. TGA-FTIR revealed nanocrystal mass loss was only from liberation and subsequent degradation of surface ligands. Encapsulation or other protective strategies should be employed for long-term stability of these materials under conditions of high irradiance or temperature.
(© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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