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Colloidal Synthesis and Charge‐Carrier Dynamics of Cs 2 AgSb 1− y Bi y X 6 (X: Br, Cl; 0 ≤ y ≤1) Double Perovskite Nanocrystals
Author(s) -
Yang Bin,
Hong Feng,
Chen Junsheng,
Tang Yuxuan,
Yang Li,
Sang Youbao,
Xia Xusheng,
Guo Jingwei,
He Haixiang,
Yang Songqiu,
Deng Weiqiao,
Han Keli
Publication year - 2019
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201811610
Subject(s) - trapping , relaxation (psychology) , charge carrier , colloid , perovskite (structure) , fluence , exciton , femtosecond , absorption (acoustics) , materials science , nanocrystal , analytical chemistry (journal) , chemistry , chemical physics , crystallography , ion , nanotechnology , condensed matter physics , optics , optoelectronics , physics , psychology , social psychology , ecology , laser , organic chemistry , chromatography , composite material , biology
A series of lead‐free double perovskite nanocrystals (NCs) Cs 2 AgSb 1− y Bi y X 6 (X: Br, Cl; 0≤ y ≤1) is synthesized. In particular, the Cs 2 AgSbBr 6 NCs is a new double perovskite material that has not been reported for the bulk form. Mixed Ag–Sb/Bi NCs exhibit enhanced stability in colloidal solution compared to Ag–Bi or Ag–Sb NCs. Femtosecond transient absorption studies indicate the presence of two prominent fast trapping processes in the charge‐carrier relaxation. The two fast trapping processes are dominated by intrinsic self‐trapping (ca. 1–2 ps) arising from giant exciton–phonon coupling and surface‐defect trapping (ca. 50–100 ps). Slow hot‐carrier relaxation is observed at high pump fluence, and the possible mechanisms for the slow hot‐carrier relaxation are also discussed.