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Title: Room temperature synthesis of lead-free FASnI 3 perovskite nanocrystals with improved stability by SnF 2 additive
Tin halide perovskites are among the candidates for replacing lead-based ones for less toxicity and comparable optical properties. However, stability remains a challenge due to the easier oxidation of Sn 2+ than Pb 2+ . Here, for the first time, we applied the ligand-assisted reprecipitation method to synthesize CH(NH 2 ) 2 SnI 3 (FASnI 3 ) orthorhombic perovskite nanocrystals with an average diameter of 7.7 nm and a photoluminescence emission at 825 [Formula: see text] 2 nm (1.5 eV). The influence of synthesis parameters, including precursor solvent, precipitation media, temperature, and time on optical properties of nanocrystals, was studied. By incorporating SnF 2 , the stability of the nanocrystals was improved, and the oxidation from FASnI 3 to FA 2 SnI 6 was significantly delayed, which was quantitively demonstrated and confirmed by observing the characteristic diffraction peaks of the perovskite phase using x-ray diffraction at various exposure time to air. The addition of SnF 2 is optimized to be 6%. The FASnI 3 nanocrystals stayed stable for at least 265 days under N 2 storage at room temperature and relative humidity of 20%.  more » « less
Award ID(s):
1751946
NSF-PAR ID:
10434227
Author(s) / Creator(s):
;
Date Published:
Journal Name:
Applied Physics Reviews
Volume:
10
Issue:
1
ISSN:
1931-9401
Page Range / eLocation ID:
011404
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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