Title

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

Publication Date

10-16-2019

Department

Ames Laboratory; Chemistry

Campus Units

Chemistry, Ames Laboratory

OSTI ID+

1572380

Report Number

IS-J 10067

DOI

10.1002/cphc.201900432

Journal Title

ChemPhysChem

Volume Number

20

Issue Number

20

First Page

2647

Last Page

2656

Abstract

Lead halide perovskites possess unique characteristics well‐suited for optoelectronic and energy capture devices, however, concerns about their long‐term stability remain. All‐inorganic CsPbX3 (X = Cl, Br, I) perovskite nanocrystals have been reported with improved stability. We investigate the photo‐ and thermal‐stability properties of CsPbX3 (X = Cl, Br, I) nanocrystals by electron microscopy, x‐ray diffraction, thermogravimetric analysis, ensemble and single particle spectral characterization. CsPbBr¬3 is stable under 1‐sun illumination for 16 h in ambient conditions, although single crystal analysis indicates the luminescence states change over time. CsPbBr¬3 is also stable to heating to 250 °C. Large CsPbI3 crystals (34 ± 5 nm) are the least stable under the same conditions; and with heating, the γ (black) phase reverts to the non‐luminescent δ phase. Smaller CsPbI3 nanocrystals (14 ± 2 nm) purified by a different washing strategy exhibit improved photostability with no evidence of crystal growth but are still thermally unstable. Both CsPbCl3 and CsPbBr3 show crystal growth under irradiation or heat, likely with a preferential orientation. TGA‐FTIR reveals 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 under conditions of high irradiance or temperature.

DOE Contract Number(s)

AC02-07CH11358

Language

en

Department of Energy Subject Categories

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Publisher

Iowa State University Digital Repository, Ames IA (United States)

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