TY - JOUR
T1 - Two-phase anion exchange synthesis
T2 - Multiple passivation for highly efficient and stable CsPbCl3nanocrystals
AU - Lv, Wenzhen
AU - Xu, Mingchuan
AU - Ge, Lei
AU - Zhu, Xun
AU - Hong, Junxian
AU - Huang, Wei
AU - Chen, Runfeng
N1 - Publisher Copyright:
© The Royal Society of Chemistry.
PY - 2020/12/7
Y1 - 2020/12/7
N2 - In recent years, substantial progress has been made in the synthesis of colloidal CsPbX3 (X = Cl, Br, and I) nanocrystals (NCs). However, the anion exchange reaction always synthesizes CsPbCl3 NCs with low efficiency and poor stability. Here, first, through separating the halide precursors, mainly metal halide salts as CdCl2 in water, we propose a two-phase anion exchange method, successfully preparing CsPbCl3 NCs with a well-maintained cubic morphology and high photoluminescence quantum yields of about 95%. A controllable Cl-to-Br exchange rate is readily achieved by controlling the reaction time or the Cl- ion concentration. Benefiting from the good solubility of CdCl2 in water, Cl- ions are provided continuously, guaranteeing an adequate Cl-to-Br exchange at a high concentration of the original substrate. Rich Cl- ions, water and even the Cd2+ ions perform effective passivation of the nonradiative recombination centers likely stemming from Cl vacancies or other impurities, which has been confirmed by the transient optical spectroscopy measurements and elemental characterization. Also, the CsPbCl3 NCs reveal improved air stability and excellent photostability. We believe that the two-phase anion exchange method offers a new way to obtain high-efficiency CsPbCl3 NCs through a postsynthetic chemical transformation route, and helps to promote further corresponding applications in optoelectronic devices.
AB - In recent years, substantial progress has been made in the synthesis of colloidal CsPbX3 (X = Cl, Br, and I) nanocrystals (NCs). However, the anion exchange reaction always synthesizes CsPbCl3 NCs with low efficiency and poor stability. Here, first, through separating the halide precursors, mainly metal halide salts as CdCl2 in water, we propose a two-phase anion exchange method, successfully preparing CsPbCl3 NCs with a well-maintained cubic morphology and high photoluminescence quantum yields of about 95%. A controllable Cl-to-Br exchange rate is readily achieved by controlling the reaction time or the Cl- ion concentration. Benefiting from the good solubility of CdCl2 in water, Cl- ions are provided continuously, guaranteeing an adequate Cl-to-Br exchange at a high concentration of the original substrate. Rich Cl- ions, water and even the Cd2+ ions perform effective passivation of the nonradiative recombination centers likely stemming from Cl vacancies or other impurities, which has been confirmed by the transient optical spectroscopy measurements and elemental characterization. Also, the CsPbCl3 NCs reveal improved air stability and excellent photostability. We believe that the two-phase anion exchange method offers a new way to obtain high-efficiency CsPbCl3 NCs through a postsynthetic chemical transformation route, and helps to promote further corresponding applications in optoelectronic devices.
UR - http://www.scopus.com/inward/record.url?scp=85097062330&partnerID=8YFLogxK
U2 - 10.1039/d0tc03602a
DO - 10.1039/d0tc03602a
M3 - 文章
AN - SCOPUS:85097062330
SN - 2050-7534
VL - 8
SP - 16083
EP - 16091
JO - Journal of Materials Chemistry C
JF - Journal of Materials Chemistry C
IS - 45
ER -